I've watched him during his entire career, national team and all, and the common and obvious criticism is that he never ran a lot - it's also something he has admitted himself to not like. So I'm using the fact he didn't like running and pressing as being lazy, which is as fair as saying he was a gifted technically footballer who never stopped improving in that department, and in fact "still has it" judging by some recent benefit/charity matches they've done (also Stoichkov's got a golden touch for his age). He did win thins and he was awesome, but he was always, ALWAYS, paired with someone willing to do the running part for him.
It's also why he's not really loved for his national team form as we needed someone to lead in tough times and him hiding and waiting for the ball up top was frustrating - the exact opposite of Lewandowski for Poland currently.