Agreed. Serving is super annoying in terms of placement, which is annoying but it means I need more practice. But in terms of movement, it is way too slow. The unforced error/winner counts are ridiculous, and because of sluggish movement, some of the winners you can get are just ugly, ugly shots. Plus, volleys are tough for no reason at times. I will get there, and hit the button to volley but I still get passed when it's hit right at me.
I have these issues as well.
For the record, I'm good at TS4. Not world beater amazing, but good. I play career mode, vacillating between Very Hard and Expert (anyone that plays in career mode knows there's a huge leap between career VH/E and regular quick play difficulty), and I do alright, winning most matches...Grand Slam Semis and Finals are a challenge at that level, I probably have a .500 record so far.
Even at that level, I'm hitting 25-30 winners in a 2/3 set match, and I'm making 2-4 UEs on average. If I lose, the opponent is hitting 20-30 winners and making 1-2 UEs. It's not realistic at all, and it's annoying how ugly things can be sometimes in the game.
An even bigger issue for me (which I've stated 400 times in this thread) is the crap career mode in TS4, and the weird quirks with opponents in career mode (IE Federer/Nadal/Djokovic/Murray serving between 95-105MPH on 1st serve, while Tomic and Blake are two of the harder serves in career mode...).
I will be willing to forgive a lot in GS2 (for instance, I never use the female characters, so if Sharapova hits a 1HBH, it's no skin off my back) IF the career mode is great. More than one potential event a month, better player builds, more realistic gameplay from an AI opponent (sounds like this is the biggest issue), better venues, and better matchplay options. It's pretty horrible in TS4 that your options are: All Super Tiebreaks, Super Tiebreaks in some events, One set in Masters, 2/3 in Slams or, all long 2/3-3/5 set matches, even at the minor events...There's got to be something in between.
Anyway, sorry for the rant. My XBL membership expired, so I can't try the game. I'll probably rent it when it comes out to see how I feel about it, but I hope it brings what I'm looking for to the table.