Having a selection of party members to choose from is great (though I'm hoping for even more in DLC) but having to go back to camp and go through the same dialogue dance every time just to swap one out is a real pain.
For example, I finally recruited Karlach (should have done it sooner, didn't realise she was a party member) but I already had a full party, and there's a camp of baddies nearby that she wants to wipe out with your help. But because there's no way to send someone else to camp, she goes there automatically and I have to go to the camp, pick someone else to leave behind, go through their usual dialogue about being unhappy at being left behind, and yes I'm f'ing sure just like the last 5 times, and only then can I go to Karlach, add her to my party, and complete the quest that's 10 feet up the road from where I found her.
We really need a menu for quick-swapping party members; it shouldn't be too hard to add this to the party management menu (the one for switching characters, grouping/splitting the party etc.), just let us select a portrait and hit a button to swap then show the other available characters so I can sub them in. It might make sense to also add a similar menu whenever recruiting someone while your party is already full, i.e- give us the option to replace an existing party member with the new one.
That said, what I would love even more is the ability to have a larger party; my actual D&D groups are usually 5 or 6 player characters. It would require the game to scale the difficulty though (give enemies more HP the more party members there are) but this could also be good for going the opposite way, e.g- if a player wants to run with fewer characters, or even solo, that should be possible too (scale enemy difficulties down a bit, though it should still be tough due to action economy).