i voted great. this was definitely a big step up from Bastard production wise, and even if some of the lyrics falter, there's definitely some memorable verses to be had on here. that, and i loved how much Tyler really bares all as well as the progression of the concept the first, especially at the end where
overall, i'd say this is a real grower. it might take some time for it to stick, but when it does, it's a really memorable release, especially for hip-hop.
and no i wouldn't call them mainstream, not with how their rhymes and production is. and with how tight knit they are as a collective, i doubt that they'd so easily sign on to feature on songs with people they aren't already cool with.