No, he's asking all the right questions. He's got a Sony TAF-700 which along with the TAF-800 (444esX and 555esg) which is a fabulous amplifier. It's built to an excellent standard and performs faultlessly. How do I know? I've got a 444esxII, a 333ESR and a 730es (same as each other) as well as probably another dozen ES pieces including two TAN77es power amps and 4 TAE77es/d preamps, several DATs etc.
The only real contenders to replace the Sony would be the current range Yamahas. The Luxmans are too expensive and honestly not up to the standard they should be for the price. Personally, having played with them all (Yamahas) including the AS-3000 and studied their schematics, construction and finish, I wouldn't be swapping any of my Sony gear for them, even though I could have bought them at cost.
There's absolutely no doubt whatsoever the quality dropped off a cliff when Yamaha purpose built the Malaysian factory. The first few batches of receivers (low end 2 channel ones) in 1992 came off that line and about 50% of them went back. I refused to sell receivers and CD players out of the Malaysian factory and when they started speakers- oh my goodness, they were bad. But the trouble is, even now, 26 years later, the speakers out of malaysia are still poorly made inside. The cabinetry is dreadful. Sure the rest of the lines have improved, but they needed to.
But I digress, the AS-2100 is nothing special. It may look the goods from the outside, but I am going to bet they will be landfill in 10-15 years due to the entire amplifier being run by a completely unnecessary micro and riddled with SMD electros. I do not need a stinkin' microprocessor controlled 2 channel integrated amplifier. The most I will tolerate is remote volume and source selection via the micro. The Yamaha is SMD, all lead-free, all not component level repairable on the low level boards. Even the amplifier boards are riddled with SMD.
The placement of this IC, uncovered means any and all dust and detritus will likely cause issues down the track, especially where moisture is concerned. The unit I saw had vents in front, but the main horizontal board and its IC only had a small central piece of metal over it- leaving the most vulnerable parts exposed.
View attachment 32478
The Sony on the other hand uses some of finest Sanken outputs ever made, is completely discrete through hole and every part is still available to repair it nearly 30 years after it was made. It's got a fantastic transformer, a chassis unlike anything else (Gibraltar cast), and solid, grub-screwed knobs, no superfluous BS and looks great. OK, it doesn't have meters, but trust me, I turn mine off most of the time on my big amps.
The OP would do well to locate a Sony TAF-730es (for the UK) or a TAF-333esR (Japanese/Asian with Rosewood sides) model. These were two years after the 700es and for whatever reason, they sound much better. They also tested basically without flaws.