Personal feedback on some features, mostly negative, not because i dislike features themselves, but they was implemented not so great and caused frustration in most playthroughs after first one.
-Offer of vassalage
Yes, it's awesome to receive letter with offer and each time you decline it your relationship goes down, again and again. Sometimes you chase bandits, click to move to them and done! You are a vassal now, because your cursor was exactly over the button "accept" when offer of vassalage number 271 arrived and you was trying to do something else.
-Companions, their personalities etc.
For me it was one of the most annoying parts - it's fine to learn their stories in first playthrough, but after this they keep sharing their stories, again and again, complaining and annoying you.
"Look my lord this is Suno! I am from here or maybe i was here! I'll share a story about Suno with you!Look! Look!" - No, my dear Firentis, this is a mod, Suno doesn't exist on this map and you are dark elf now, also you became a girl, congratulations and stop ruining my immersion.
Basically talking companions is like a sign from developers "Listen, we don't think anyone will play this game more than once or twice, so we'll just shove all 200 pages of lore in your face and we don't care do you like it or not, and there is no option to disable it, so, enjoy!"
Nowadays thanks to all those interactive and talking companions (in modern games in general) in any day i'll rather choose silent and reliable companion without predefined set of skills when i can decide what will he be and doesn't feel like half of his possible progress was wasted on something i don't want to use in current playthrough. Sadly, there is rarely any choice given.
Thing is - i remember names of Ymira, Deshavi, Matheld and Artimenner even after all this years, but if you ask me what was names of companions from mass effect for example - i'll honestly tell you that it's not like i forgot their names, i didn't even cared if they had names in the first place. Sorry, ME fans. So, my complains in this case not about the feature itself, but rather how it was implemented. And realistically when M&B was designed and companions was implemented it wasn't possible to predict how many mods will be created and what kind problems for modders it will add. Actually, modding itself wasn't even planned at this point probably.
-Feasts
Didn't had any complains about them. Free reputation, tournaments each day, good times.
-Character creation
It wasn't on the list. My complains about it - It does work. As long as you are in Calradia and it's your first or second playthrough. Or if you don't have specific goal in mind before you even start another playthrough. Otherwise it just doesn't.
It is immersive. I was watching others starting their first game in Bannerlord for example and people actually liked that system when you choose what was your life before game itself starts and it is affecting your stats. I had same reaction years ago in M&B but.. now, 17(?not sure) years later, i don't like it. First impression is nice and all, but when it's gone and forgotten you look only at system itself and what you can use this system for. And it's not a character creation system, it's rather "character, who is a horse archer" creation system. I am creating character in Bannerlord, i carefully choose each and every option, i want to concentrate on athletics, 2 handed weapons and medicine. Result? 3 focus points in Riding, no any another skill have more focus ponits than riding, two focus points in bow. Two handed weapons and medicine 1 focus point each, maybe 2 occasionally thanks to differences in choices. Some random points scattered here and there, but none of them important because i wouldn't use any of this skills anyway, thanks to current character developement system. I was a horse archer in M&B all the time without even realizing it. Eventually i had 2 handed cleaver and athletic for sieges, sure. But now in Bannerlord when i can actually develop character by using skills all i can create in a character creation stage is a horse archer.
Do i like all those immersive features in general? Yes. Do i like when features jump in your face repeatedly when you are trying to do something else? No.
I would rather choose design where if i want to learn some lore from companions i can talk to them in the tavern, about this or that, maybe drink there together or play games. This is just an example, i don't want to play with companions or talk to them, thanks to modern game industry, where it just became a trend to add dozens of voiced npcs who share their stories and feelings with you, fully voiced, with loooooong subtitles in the end. For some reason people calling it a "game" even if it didn't had any kind of gameplay in it. Immersion in general is cool, but it's just to easy to ruin gameplay if you focus on immersion only.