1. The Presence Of NPCs: Arguably the most notable difference, in personal experience with my own parties over the last 10 years I've noticed players may be reluctant or shy to roleplay in character when speaking to one another or pursue possible cross party agendas but will be more than willing to chat to NPCs and use them like puppets. Part of this is due to player personal preferences some groups dislike having inter party conflict or romance due to possible issues with player/character separation (who hasn't heard stories of groups dissolving after two or more players took a character death by another party member personally). Another issue is simply that some players simply will not know what to do or discuss because they are talking to another character who already knows everything they might talk about or alternatively certain players (particularly newer players) may feel uncomfortable with been in the spotlight. While there may be NPC's such as followers, fellow travellers or captives in a camp fire scene more often than not the party knows the exact alliances and motivations of these NPCs (or in some cases be directly under the control of another player) so there is no mystery or risk.

2. A Variety Of Additional Purpose: A camp fire scene has arguably 3 core purposes: to rest, eat and heal, to create a temporary area of safety and to allow time to perform tasks such as changing equipment, interrogating a captive or performing a complicated spell, wait for a contact to arrive etc. A Tavern can cover all three of these in its own way and provides more possibilities such as gathering information (both discreetly and overtly), indulging in celebration and vice such as drinking and wenching, acquiring supplies and wealth (through merchants, fences and gambling) as just a few examples and because of this it retains more of an important role even into the later campaign as the party gain access to versatile magic. In addition a campfire scene in nearly all scenarios occurs while the party is travelling between locations (even if that location is between floors in a dungeon) whilst a Tavern might be a stop between locations or lie in the heart of destination if it is within a city.

3. Location And Illusion Of Safety: Even if a Tavern is owned by the local thieves guild and has a two people drinking in the corner who a group suspects wants them dead a tavern will nearly always seem safer than a camp. This may seem a strange claim but when analysed it is down to the simple fact that far easier for both a player and character to identify possible risks and sources of danger. After all you only really have to analyse the people within the tavern, if your worried about been killed in your sleep you barricade the door of your room and check for possibility other entrances, if your worried about poison you eat your own food and drink, in the case of a fight its often well lit and attackers are visible. There is no worry about possible roaming monsters, the elements, the possibility of the shelter collapsing and all the other issues that may affect a camp and because of this players are more likely to engage and take risks and be involved in scene where in a camp scene its set up, make a strong fire, deploy spells and bunker down.

4. Player Familiarity: Simply put many players and dungeon masters are more personally familiar with the concept and imagery of a tavern through media and personal experience making it far easier immerse themselves into the scene. Often camp fire scene in films and book shows the characters recuperating and mentally relieved at the break from the events of the day or alternatively nervous and in fear of what may occur during the night, but because of the detachment between the player and character and often the emphasis on heroic roleplay its difficult to portray either of these feelings in roleplay.

1. It allows wilderness classes such as Rangers and Druids to bring their skills forth and gives them some time in the spotlight.
2. It creates a scene where characters can interact with each other in a casual, non stressful manner.

• I've introduced more encounters with other travellers on the road such as day to day merchants, PCs in the wilderness may also encounter stray animals, a lone hunter or even another adventuring party though I try to limit these encounters. It helps bring detail to the world and helps with players who have trouble role playing with other player characters.
• Describing possible weather and conditions that may affect possible camp sites, this combined with some detailed descriptions of the land have lead to rather entertaining side adventures as the parties refused to stop and sort out better camp sites.
• I also have a general rule of a single camp fire scene per journey (unless the players want more or a event causes another) unless the journey is particularly short. This reduces the problem of the party growing overly wary when questioned about camping as mentioned earlier.

Music
Music in the wilderness means you are not afraid of being attacked and what reminds characters of home more than the songs of home. +1hp per level per night in camp where music is played. The idea came for having bards as hirelings, but I've allowed characters to buy and play their own instrument. This costs some money and takes up encumbrance space. And how about the noise? I wouldn't want to penalize too much, or players would never play music in camp, maybe just a +1 to encounter rolls.

The Hearth
If the campfire is the extension of the hearth, maybe it should offer some protection against the dark. I'll repost an idea here:

A cleric, or anyone versed in the Old Ways, can take a stone weighing a half-stone or more from the night's fire. By incorporating it into the next night's fire ring they make that fire a hearth. Each night of doing so makes the hearth magic stronger. Undead and shape changers can not enter the light of a true hearth.

Half-stone is ~7 pounds which is one of my simple encumbrance slots. I'm not interested in the bookkeeping part now. Maybe just, using the hearth a second time on gives the protection, but skipping a use in a fire will mean you have to break the stone in again. Particularly old stones taken from ruins or abandoned cottages might function as magic items that give extra bonuses. 

The Campfire Fuel
Telecanter discusses a hearth stone idea that is tremendous. In the same vein, I like the idea of a particular type of wood helping the party. If those with botanical knowledge harvest these special woods to burn in the fire they enjoy some varied bonuses.

Wood with its effect
Barkbane This thick-barked wood is purported to keep all dogs and wolves at bay and is found to be nauseating to lycanthropes (any lycanthrope suffers a small attack penalty while fighting near barkbane).

Bloodthorn This reddish wood has severe thorns all over it. Those who have open wounds will find they quickly close and coagulate (a small immediate healing bonus for those affected by naturally occurring battle wounds of the cut/slash sort).

Greencloak This leafy, vibrant tree has wood that burns with a very thick low-laying smoke. Anyone who burns greencloak is somewhat obscured as the green smoke helps hide them. The GM may institute a small penalty to any foe trying to spot the party’s campsite.

Wyrdwoode This white, gnarly wood burns with a pale yellow smoke. The smoke has a calming effect on all persons and animals nearby (horses won’t spook as easily, the party familiars will rest easily). The wood’s effect may reduce the duration of any sort of agitated condition or mental state (shaken, scared, etc.) or remove the effects of a spell that affects the target’s mental state.