In all fairness...hp is not just hp. In stock trim a Mk IV Supra has a much nicer torque curve than the 3000GT. And, the Supra also loses a lot less hp to parasitic drag through the driveline than a 3000GT does. The first one is just the way it is (largely due to the fact that the Toyota's six is an inline engine.....better torque than a V naturally by design) and the second one is simple physics as it requires more power to drive four wheels than two.
Not to mention if hp levels aren't in the stratosphere...and sometimes even if they are....AWD is not the end all be all of acceleration. Take a look at the current 911 Turbo with AWD, and the 911 GT2 with the turbo engine but no AWD.
If you opt for the 444hp engine option on the std AWD Turbo hp is nearly the same as in the GT2. The GT2 does weigh less than the Turbo, but most of this comes from it's lack of AWD. A GT2 will leave an AWD 911 Turbo like it is tied down.....Where did the awd acceleration advantage go?. Part of this is the 911's brutal rear weight bias, but not all of it.
AWD definately benefits the 3000GT chassis as it is fwd without it and that is the worst of all worlds. However, from a strictly performance oriented standpoint, unless you are speaking about something with a weird and undesirable front/rear weight bias like a pickup, I do not believe awd offers as much of a peformance advantage over rwd as it offers easier accessed performance.
In other words an inexperienced driver is a lot less likely to get himself in trouble in the 911 Turbo than in the 911 GT2....hence the purpose of the AWD system. But, an experienced driver will drive that GT2 faster...or at least Porsche thinks they will. Put simply Porsche took the awd OUT to go faster, not put it in.
Also, in lower powered (stock) engines...especially those without a good amount of torque. AWD has a tendency to bog the engine down on launch. Folks, put simply, that isn't good. AWD had it's advantages, but it also has it's downside too.
Also, I am no Supra lover.......I would take a last generation 300ZX (Man those things look good.), a 3rd gen RX7 turbo, or probebly even a 3000GT over the Supra as the Toyota just is not my cup of tea. But facts are facts and 3000GT's were never faster than Supra MkIV's stock....unless it was raining.
But then, a LT4 C4 Vette would out 1/4 a Mk IV Supra, so should we all bow to the C4 Grand Sport and should all MkIV Supra guys go throw themselves from a cliff.....of course not. I have a line of cars I would pick over a C4 Vette. But, like a car or not you have to give it it's due.