If anything, my observation of the Premium Members is that they tend to be older, somewhat less attractive and are using the Premium status to try and attract some attention. I'm not criticizing that approach; I do it to, (and got Background Verified), I'm just saying that I haven't noticed any trend for super hot Pros/Semi-pros to be Premium Members.
The topic that forked off in this thread is the TER vs SA experience. I think they're just different. Having seen a few SBs now, I'll certainly say that SB sex is NOT escort Sex. Not even close to a good escort in most cases. In just physical terms, I've only had one experience on SA that is in the high end TER range, and she's a semi-pro about to go pro. The others are sweet, often quite into, but not pro level, and that should hardly be a shock, right?
OTOH, the sweetness of a newbie still learning the ropes, the much longer dates for much lower prices, the feeling of a real connection, etc, these are what can make SA so wonderful.
The long conversation threads before meeting, and the many such threads that lead to nothing can be frustrating. However, I've met some lovely young ladies, and even amongst the ones that lead to nothing, or nothing beyond coffee, I've had some interesting conversations with interesting people. I suppose most hear don't care about that, but I do.
Finally, SA is very different than TER in the sense that the SD/SB interaction is what you want to make it, and I like that. TER has "rules" and I chafe at some of the rules in the escort world, and simply find SA a better fit. And TER ladies are still there; it's not like the two universes are mutually exclusive.