Sorry for comin so late, been away.
I can only vouch for my experience with Apexi AX53B60's. I've had em on my GTR for about 4 yrs, but only done about 12,000k's. I do remember they cost me a s**t load, I think about 7G's back then.
I reckon they're great, they aren't as quick responding as alot of you are hearing, but may have a fair bit to do with cam timing also. I've found them pretty awesome for street and track work, but a little lacking in response in a big heavy car for drifting( compared with the previous N1's). I get full boost by about 4800rpms, and it pulls hard to 9,000, but I pull the pin at 8. They're rated to 1.7bar, and I run mine at 1.3bar for around 300RWKW and 11.1 secs. I will be pushing them harder once I've run in my new forged bottom end.
A good mate also has them on an RB26, but in a GTS-t, and with bigger HKS272 cams, it's seen 365RWKW's on the same dyno @ 1.6bar.
On another note, they apparently have a "teflon" insert on the inlet side to limit wear on the compressor wheel, allowing a longer service life. I hope so! The full kit is very comprehensive, with all braided oil and water fittings, 'cause they're based on IHI components, so be careful if buying second hand. Also don't forget to port the exhaust manifolds!
I reckon they're perfect for a street/circuit/strip all-rounder. Cheers!