It is entirely possible that elance is great for non-technical jobs.
The issues I ran into were providers who have great ratings but who can't do the job! Later I found out that elance has a loophole where buyers who disputed or cancelled projects are not able to leave feedback. So you're not getting the full story when you look at a provider's history.
elance doesn't really care about this. So you have a huge portion of freelancers on elance who cosmetically pump up their ratings to get more jobs and then either farm them out to others or do a shoddy job themselves. when/if the job goes into dispute or is cancelled it disappears from their history. if the client is dumb enough to be happy with the crap work, they get a nice rating in exchange for turning over the final code.