no problems with alibaba as the intermediary platform so far. maybe i've been a bit lucky, but i've immediately found a reliable chinese manufacturer for my goods and i'm in continuous talks with the employees per email and skype. they are very friendly and helpful. the good guys care about their reputation.
in any forum thread that deals with alibaba, there is at least one of the commenters who repeats that mantra of "don't ever do business with a company with that name". that's so completely dumb by now, that i really don't want to comment on this.
on the other hand, as far as i'm concerned with my personal business, the sceptics are welcome to keep prevailing. less competition is always a good thing for a merchant.