Lots of questions ..... AMP = Asian Massage Parlour. MA= Massage Attendent.
AMPs are generally more spartan than high ends spas. Some are nicer than others. Some have showers in the room (rare) and others have nicer looking rooms.
There is the rare youngish MA at an AMP but you are correct, usually they are older. IMO the older ones are often more friendly, more service oriented and more skilled. There is always exceptions to the rule.
Often when arriving you may be asked if you have been there before, it may be beneficial to say yes, but not recently - unless you have been recently, then eagerly say so and tell her it was so wonderful you had to come back. If they ask who you saw it was Coco or Cici or Bobo or Lily or Mimi .... one of the very common names of AMP MAs. Or say you forgot her name as you go to so many spas and see so many MA. You want them to trust you are a repeat customer so the menu later on is not restricted. Not all that different from non-asian MPs.
If you tip $100 for an HJ you've tipped way too much. AMP MAs will often give you a menu with their hoped for compensation. If you are nice you can usually respectfully negotiate a bit. $100 tip would be near the top end of the menu in most places. I've heard some top end at $140 these days. Menu varies greatly from place to place. If they ask what you'd like to spend they will offer little at first, again respectfully try for more.
The massage is usually better than your CMJ or Brass as the girls are (mostly) actually trained at massage. On the flip side not all AMPs will offer things like body slides and the experience is likely not to be as sensual overall. You may find the occasional super sensual experience but it is not as common.
Granted, I do not frequent AMPS like I did years ago but I suspect the info is valid. I was at one a few months back and the routine seemed the same, just higher tips than years ago. I frequent Asian escorts these days, check reviews for Asian Milf Factory - my go to place. Older women but most of them do very good massage and you don't have to worry about a menu and being disappointed that something you want is not available. If you go for 45 minutes you have lots of time for fun and then massage at a cost about the same or less than an AMP.
I went to AMPs when I first hobbied years back and loved the thrill of seeing how far I could get, yet enjoying a damn good rub. As I got older the thrill wore off and I wanted a sure thing .... thus the switch to escorts. Either way is fine, there is no right or wrong, better or worse. Whatever gets you off at the end of the day. Whatever you decide be sure to post reviews (keeping in mind MA limits) to get this board back to sharing as it was when I first joined.