When I said I haven't seen him play I didn't mean literally never. I've seen him maybe twice. But yeah, I can't really comment on Neymar but I really doubt he'd make more of an impact at a European club than Dzeko would. He may go on to be better than Dzeko, he may not. If we're going to pay the same amount for either of them, Neymar would be more of a gamble.
Having said all of this, we need fullbacks first!