Ratings can be really misleading.

There are plenty of cases on Elance where the contractor has literally bought a positive review from an unhappy customer by discounting the price. In a few cases, Elance has actually interceded and revoked bidding privileges from companies that were found to be doing this on a large scale, but it happens a lot more than they are willing to admit. We've had vendors try to do that with us more than once.

Likewise, communications are only so much of the project. I've had project managers that I had lengthy emails or IMs with that I thought had a very clear understanding, only to receive code back that grossly missed the mark, or an application that basically worked, but when you looked at the underlying code, it was the biggest mismash of kludged-together routines from other applications that it would be a nightmare to fix or modify if a bug cropped up or an additional feature was needed. Or, in a couple cases, a project manager that communicated wonderfully and promised the moon, but nothing was ever delivered on time or as agreed... they'd always be quick with the heartfelt apologies, which were followed by more delays and problems.

And there have been some great experiences as well. There's one coder I wish I could find... I'm afraid he may have passed away... who did amazing work, that always worked perfectly the first time, was delivered on time, and in budget. But those guys are few and far between in my experience.

In my opinion, the only really safe way to approach working with an offshore coder is to start with something very small and non-critical, evaluate what the experience was like (were they on time, did they do it right the first time, was the code clean and well written, were they responsive and readily available) and only then move on to a larger project. Even then, it's still a little iffy.

In short, it can work well, but you have to be really, really careful. I've been using offshore coders and designers for a bit over 10 years, and even with that experience, I still get snookered every now and then.