I've been slowly playing through Baten Kaitos because because I lost a bet with a friend, so my impression of it might've been tainted from the start, but I'm really not enjoying the battle system.
To start off it's a card battler/deck builder, which I already don't like. Seeing cards in a game is always a big turn-off for me. The basic gist is that you've got a hand of cards and you play one or more of them when you're attacking or defending. It heavily encourages combos where you play multiple cards at a time.
Only certain cards can be used for offense and others for defense, so it's very common to run into a situation where you've got a hand full of defense or combo-dependent cards (card that require a combo to already be in progress). When that happens, you can't attack and usually need to waste one invalid card to essentially skip your turn. Playing defensive cards on the defense phase will let you cycle through them quicker, but if the enemies decide to not target that character, you won't get a chance. It feels like it should be easier to discard stuff because of that.
Another bizarre decision is the class upgrades. They increase stats, deck size and combo length, but they also reduce the amount of time you have to play your cards. You start out with unlimited time, but by class level 5 (where I am), you have 10 seconds to make your choice on the attack phase. Defense turns require you to select cards based on how quickly the enemies attack. For some enemies' first attack, it's very difficult to play something in time.
I'm playing the remaster on switch, which has some nice quality of life features like speedup - very useful feature because the battles are agonizingly slow normally. But wait it's actually kinda broken. Setting battles to 200% speed makes everything faster, meaning you have half as much time to play your cards. Some of the timings can be tight at 100%, and the game gets nearly unplayable at 200%+.
The highly random nature of drawing cards is probably the most frustrating part. Multiple times now I've lost a 10-15 minute boss battle because I just couldn't draw any healing items, while clearing it easily the next time when the draws were a little better.
I'm really trying to like the game, but it kills my mood when it decides to be uncooperative.