Not ALL of them grenade
I have been running my BD Power HX40 since late Jan. 2001, so far so good. I see 40 psi's on a daily basis and can easily hit 45 psi's with the TST box on setting 6. Lag... . yep, there is some lag, but that disappears after about 2 seconds of throttle, then look out as the boost throws you back in the seat. If mine went South, I'd replace same with another in a heartbeat.
The twins do look sweet, but at what price ? Is the HX40 used as one of the turbos, or is it a HX35/HX55 combo ?
Another point... I don't abuse my HX40 in my mind. No stomp shifting, etc. I roll the power on smoothly and release the throttle in the same way, I believe the turbo shaft is much happier that way.
I don't know if it matters, but I followed Mike's advice at A. W. D. when I had the turbo installed. His advice was to build the boost slowly, adding a bit more with each pass, kinda like curing the turbo like you cure a woodstove. Seemed to work for me.
Scott W.