Chambers is effective attacking as well, he seems to get beyond the man and get the cross on his fair share of times. The reason he isn't quite as effective as Clyne is probably the fact he's about 3 seasons behind experience wise.
It does beg the question though, how long will Clyne be happy to play second fiddle considering he left Palace to get games in the Prem? At least if we do need to sell we'll get a good fee for either of them.