I have the -9 turbos on my R32 GTR, they are awesome with Apexi PFC, 3.5 inch full exhaust, cams, cams wheels, 044 intank, 700cc sard injectors, stock exhaust & inlet manifolds, on 18psi made 362Rwkw.
Very responsive minimal lag. They are rated at 320hp just under the -5s 350hp, i will have to post up the dyno chart but seat in pants feel is great i guess from what i have been reading they are in between the -7 and -5s for response but do pull hard all the way to 7750rpm so i dont feel them dying out at all till then.
My 2 cents worth.
Dave.