Well, one thing you need to keep in mind is that was Amare's first game action since his "return" if you can call it that last spring. He again took a lot of time off after that for the surgery on his other knee, and then started the re-hab process over again in order to get into the summer league. You should be encouraged that he played big minutes in each game, even playing in back to back games. I don't think it's fair to judge his jumping ability/quickness until he has some more game time under his belt. 3 summer league games isn't going to get him back to vintage Amare form. We may never see that again anyway.
I was reading an internet article about him the other day at the Team USA camp, and the word around there is that he is improving everyday.
It's going to take a lot of time for him:
1. Get his legs under him again
2. Be able to trust his knee again
3. Figure out what limititations or lack therof he will have from the knee
4. Just get back into the basketball mindset again.
I'm not saying he'll ever return into the old Amare that all of us were lucky enough to watch over the last 4 years, well, 3 I guess, but give him some time before you draw conclusions about his game post injury.