On their debut, the perceptionists -- Boston-based MCs Mr. Lif and Akrobatik -- prove themselves the most precise and effective word-slingers in alt-rap, dropping rhymes packed with witty wordplay and shout-outs to teachers, struggling teens and their own integrity. Their luxuriant funk will appeal to hip-hop lovers who don't need to study every word, but their flashy interplay and statements-of-principle like "Corny niggas switch it up and rent it to Viacom/But it was taught to me ear...