what´s this?

that site will attract a lot of players from India for the software. Other types might be OK. Just look for something you can do and bid what you can to be happy and let it go of another guy underbids you. Do niot chase the nid down. The site is made to attract downwards bidding.

How they assess the quality of th work and pay for it prior to assessing or or how can the worker make sure he gets paid are aspects that might be a problem.

suggest you look here, read comments etc

http://groups.google.ca/groups/search?hl=en&oe=UTF-8&q=getafreelancer.com