Well, I wouldn't say that it's a myth perpetuated by Honda speed freaks. One of the biggest and baddest cars in the import scene is the Eclipse GSX. Lots of ppl have messed with those for years.
Logically, it just makes sense that with the drivetrain propelling 2 axles, resistance increases so the powerloss in the driveline increases as well. So along with the standard front axle, you have the rear drive shaft and that connects to the rear LSD. That equates to 2 coefficients of drag that must be overcome before the tires can move an inch. But the benefit of that along with the rear LSD is near zero wheelspin upon launches. I'd say it's a pretty decent trade-off myself (but then again, I'm a pretty crappy launcher and I sit there and spin my wheels off the line

). But then again, FWD inline-4 need to be punished at high RPM to achieve the torque the Subaru makes at lower RPMs.
The efficiency of the drivelines do matter though. Recall the issue of SCC with the MR2-Spyder vs. the Miata. The MR2-Spyder dynoed higher at the wheels due to an efficient driveline (124 HP) and the Miata (113 HP) because of the tranversely mounted engine.
I would say the myths most prevalent in the import racing crowd would be the HP/L thing and the HP/LB. There are lots of heavy cars that are fast and vice versa.
will
Y2K Silver Celica GT-S 6-Speed
wants to get a Scooby soon!