Apart from the story aspect, pre-generated companies are more interesting from a tactical perspective; instead of leading a power-gaming team of killing machines (which is damn boring), we are leading a real group. We have to adapt our tactics to the available characters, accept their weaknesses and suboptimal attributes. We have to accept that not every combination of classes will be available to us (e.g. due to alignment differences, as in BG1), that we will have to use less powerful weapons (because our warrior has skill points in short swords). We will have to think about how to use less powerful spells etc. It amuses me much more and games such as BG1, BG2 and Drakensang are ideal for me in this respect.
For a more story orientated game (like PS:T) I like companions better, but for a more combat heavy game (like BG or IWD) I'd rather have full party creation. The problem with one character + companions is that it limits your party building and indirectly limits your only character creation too. Want to play a bard? But there is a bard companion at the start of the game, do you want to have 2 bards? Probably not. You want a party to have a druid, a barbarian and a ranged fighter? There's no companions in any of these classes, guess you can only have one of these, and it must be your main character. Maybe I don't want that short sword specialist fighter with 15 strength? Or maybe the only available cleric is good and I wanted to have an evil PC and party?
And that is the optimistic variant (BG) where most companions are at least tolerable and not completely forced on you, in NWN2 for example not only are some companions shit, but you have no option to get rid of them and are forced to have them in the active party on many missions, which can fuck right off.
It's true that full party creation has better potential for power-gaming, but it's more of game-specific encounter design and general difficulty issue, not an issue with party creation itself. You can balance the game around full party creation just as well as you can around knowing that the player will have that short sword fighter with 15 strength. And full party creation isn't just for power gaming, you can have weird or thematic parties: only dwarves, 5 barbarians and a druid, party of monks, no spellcasters, only spellcasters, no cleric, etc. In a game without full party creation you'll usually have some or even most of the same companions every time you play and the overall number of possible party compositions is a fraction of what full party creation offers.
Besides, it's really hard to identify with a group of six, which kills the aspect of playing a role for me (because which role do you play?).
The leader that talks to NPCs? The entire adventuring party? Benevolent spirit that guides the heroes? Don't know, it's never been an issue for me.
The best thing i having party companions with their own story and quests while still having an option for party creation.
won’t work since the temptation to overcome flaws of a pregen characters will always be irresistible.
To me it's the opposite, I couldn't play Kingmaker with mercenaries, because the game was obviously designed around using the pre-made companions, even if some of them are annoying or their stats aren't what I'd like. A ton of content involves their part in the main quest, their personal sidequests and roles in the kingdom government, you could use mercenaries, but you'll miss a ton of content and generally have a poorer experience. I'd love a full party creation game using the Owlcat's engine, but Kingmaker and WotR aren't it.
