On the Sunfire Web site, the TGA-7401 is spec'd to 120 amps of current per channel while weighing 46 lbs. I had an e-mail discussion with Parasound regarding their NewClassic 5250 v.2 and asked them how it was possible for the Sunfire to have so much more current than the Parasound while weighing so much less. They said that they would have to "question" the Sunfire's specs on current by weight is part of the equation when it comes to current. For reference, the Parasound Halo A51 has 60 amps of current per channel while weighing 80 pounds. The Sunfire TGA-7401 has double the current capability while weighing about half as much. Are Sunfire's specs accurate or is something up? I am sure Parasound's input on this matter would be bias so I am looking for an unbiased point-of-view.
As I understand the technology behind Bob Carver's design, the idea is that his amps can deliver vast amounts of power by tracking the input signal and varying the amount of power delivered by the power supply. He calls it a Signal Tracking Power Supply. Conventional designs have a power supply that outputs the constant amount of power no matter how much amplification is needed. So in theory, Bob's design has a variable power supply which can be more compact, less weight (smaller heatsinks) and runs cooler. So can it deliever 120 amps constantly? Probably not. Does it deliver it when it needs to? Yes.
That said. I have a TGA-7200 for about 6 years, paired to my Anthem Statement D2v. It really is a great amp, sounds tremendous and never had a problem with it struggling with any movie or music I've thrown at it. Before this setup I had (and still have it as a secondary system elsewhere in the house) a Sunfire Ultimate Receiver II which is a full Dolby Digital/DTS processor, tuner and a Sunfire Cinema Grand 200 watt 7 channel amp. Although I use it for casual listening, it still sounds great. My brother has one of the original Cinema Grand amps. I believe he bought it in the late 90s and he still uses it today although he has upgraded all of the components around it over the years.
Now Parasound makes some great amps. In fact I almost bought one instead of my current amp. I don't think you would go wrong getting one. Demo both units and see which one you prefer.