in some P2P provider, they ask to have some feature active or desactive to work. With Bittorent client it's working, because these client has more options available, but it's not the case with the bittorent client on the NAS.
For me, it's working 90 % of all case, only 10 % not working because of these server.
also, the RATIO on some server are not updating right with the NAS. so if you are on a server that ask to have at least 1:1 ratio ... for each 1 Meg you upload, probably between 200 and 300 k will appear on the site. For now, i only found 1 website that show me this result, so i try to avoid the Bittorent client on the NAS when i need to download from that site !.