I have not built or heard the AES Superamp, but as I'm sure you know AES is the kit/parts division of Cary Audio, run by Dennis Had, who has been highly respected in the audio field, particularly for his SET designs, for years. Cary and AES have excellent reputations for customer service -- I don't think I've ever seen a bad word written about them. I remember seeing some good reviews of the Superamp when it first appeared, and some of them appear at http://www.superamp.com .

I did build another AES product, the PH-1 phonostage, which has performed flawlessly and excellently for years with my Rega Planar 3. The assembly manual was thorough, with step-by-step verbal and visual instructions. The PH-1 uses point-to-point wiring, and I believe the Superamp does the same. That means it is not as easy to build as a PCB-based design, but if you go slow and enjoy the building process, rather than rushing to completion, you should do just fine.