Ball bearing turbo vs twin scroll turbo

Hey everybody, I just wanted to see what everybody thought where the pros and cons between these two kinds of turbos. Disregarding costs and fabrication difficulties, what are the pros and cons of each? Thanks

Both are generally good, so what is the question? Bb will spool and recover diring transients faster. Twin scroll will spool quicker if the manifold is made for it, all else being equal. 

In reply to Paul_VR6 (Forum Supporter) :

Which one would people choose if they had a choice, all things being equal. I'm thinking the best of both worlds would be a ball bearing twin scroll turbo 

Ball bearing makes a bigger difference from what I have seen on boost recovery especially (transients)

Is twin scroll really much of a feature,  or is it like saying an engine has overhead valves? For instance, I know 1987 Mazda RX-7 turbo II had a twin scroll turbo, but no one is going to suggest buying a 40 year old turbo.

Those two characteristics are not mutually exclusive. The best is both, but whether or not the juice is worth the squeeze depends on a lot of other factors. 

Twin scroll works best with even, separated exhaust pulses. Best on 4cyl and inline 6s. Hard to do on a v6 and by v8 likely not worth the packaging trouble and twins may be better anyway.