Hi BTworld is dead as they moved to AtomicHD.
Blutopia and worldofp2p should be at level 3 because they have some outstanding quality encodes.Blutopia's internal encodes are amazing.
Avistaz should be level 4 as they have a huge collection of Asian movies along with some good encodes.
Also BakaBt should be at level 4 or 5 as they have included many contents which were blacklisted earlier.

Thank You!