There is a major benifit to using the haltech one over the profec B.
Working with the e11v2 ECU, you can adjust different boost levels for each gear (i.e. 1st -18psi, 2nd -22psi, 3rd - 24psi, etc.....)
Profec B can't do that. Plus the haltech is cheaper, $125
See below:
http://www.haltech.com.au/boost_ctrl_soln.htm
I had and e11v2 and haltech boost control in my previous GTR. It was excellent! Launch control tied in with lower boost off the mark and higher boost through 2nd. and 3rd, etc....
I'm not knocking the profec, everyone knows it does its job well. I am just stating if you have a e11v2 then go the haltech boost controller.