Every new update of an user interface comes with complains, I know (as developer myself) that this can be a major setback for developers, but most of the time it takes time to get used to it and some minor tweaks.
However the new UI does looks more cluttered to me. I used custom icons (square based) and they are now used as background for the several accounts, which not only mean that most of them isn't visible (because of the small buttons for the accounts) but also that the text in it isn't that good readable (white text for account name and amount). I really liked the "old" style of the accounts take a whole row instead of these smaller buttons, maybe add an option to choose? Either way, something has to be done about the readablitity.
Next on my list is that in V2 it was possible to not count the amount from some accounts with the total as showed, in this version it is possible to hide the account, but I don't want to hide it, I want to see the amount, but I don't want to have it summed up with the total. For example, I have several accounts with special purposes, money on those accounts "I can't use", so it is useless for me to see this calculated with the totals. Same goes for the "Saving Goals", I don't want that money to show in the totals, but I do want to see the progress, so hidding those accounts isn't an option.
Next is the "cards" section, it is difficult to distinguish the different cards, but on the other hand I didn't liked the old interface for them eitherm but "something" has to be done here, it is difficult to understand this part of the interface to quickly see and change the cards. I see different background colors, but don't know what they mean.