Hmm I can't check my setup as I'm on a new test rig just now.
These numbers depend on your connection.
The secret is shoot low.
I ran for ages at the wrong settings before I finally sussed them out. Now I can max out my 2mb connection no bother.
I used to have 10-15 torrents downloading all at once each at 5-10 K each and they took ages to download. Now I set it less and although I can only download 3 or 4 torrents at once, they download at about 100-240K depending on peers.
Use the built in speed checker / options setter to get a starting point.
Then increase the settings one at a time and test.
My upload is 20K and I think it was set for no more than 12K.
Something like 150 connection max.
3 torrent downloading max.
25 connection per torrent,
Start there.