Whats the Difference?

Whats the difference between the Megaupload ( http://www.megaupload.com/?d=AZ9P2NDJ ) version of the client and the gigasize ( http://www.gigasize.com/get.php?d=hmmx144mw7c ) Because I hate gigasize at the moment, and I still got the link for the megaupload one. So back to my question, is there any add ons or anything on the gigasize one?

i got my first one from megaupload and it didn't work, says version is wrong, so i guess i'mma try giga even though it's very slow compare to megaupload.

i'll go school , uploading cilent in mediafire