tried ABC....i took ages to recheck/hash every time i started it.
if you have 5+ torrents waiting... thats painfull.... and it kills your CPU to 100% usage while working that.
thats why i picked Bitcomet, it doesnt have to rehash when you start it again... for single DLs, BitTornado is still my #1, but since i got better conn and tried having 5 DLs in BT it simply didnt work out, 2 would work 3 would freeze.... pitty, its really good...
as i said...i would use Azureus if i could instal Java it needs, but because my bloody online banking has to use some arhaic version of Java when i try to run Azureus it says "no Java on your comp" :?
Torrentstorm was also pretty good for multiple downloads, but i have a feeling it slower then others and limited options....
For me one on major option is to limit global uploading, cause my DSL is 1.5/192 which means if i have 5-6 DLs with 3 KB/s...there goes all my bandwidth and i cant even surf around.....
When I first started bittorrenting I used the official client, which in those days was VERY basic and primitive. Had pretty much no config options at all, including upstream cap. Back then I had only 512kbit upstream and downstream, and BT sucked enough of that b/w that webpages timed out on me in IE when I tried to get them to load. VASTLY annoying! 
