Thanks to everyone who shares on this thread - having done my research here I decided to give it a go for a month.
Initial impressions were it's a total waste of time. Many phone numbers collected, bit of chat about meeting, then either silence or cancellations. So I gave up after 1 month as I felt I invested too much time into it.
However, totally unexpectedly, 2 of my 'prospects' from weeks ago got back to me on Friday. In fact, these were 2 that were low down on my prospect list, as I suspected were too shy or not serious enough to go through with meeting (one is 19 and at studying at a top uni, the other is 20 and works in theatre and was not very communicative over whatsapp). Both appeared to have recently joined.
Wow was I wrong. I had the most incredible couple of days. Uni student sent me some nudes and just said when do you want to meet? We met the same day, few drinks and back to the hotel. She was incredibly horny and perhaps I just lucked out that I was responsive when she contacted me! We were together for most of the day. Not a mention of money at all, and she thanked me for being so kind to her.
Next day, theatre girl messages me some filth out of nowhere, apparently while on set! I thought this is a scam, she will be asking for payment for nudes any moment now. But, to my surprise I said meet me at a certain location and she was game. We barely spoke and she jumped on me (quite literally). We had an amazing time, bought her breakfast the next day and off she went. Again, bizarrely, ZERO mention of money. She also got very cuddley and thanked me for being such a kind gentleman...
So to those who are claiming other guys are talking bullshit when they say their SB's have not asked for payment, I can honestly say they might not be lying. Now, I have literally interacted with 100+ girls in a month on SA, and wasted a hell of a lot of time, but if I can keep these 2 gems with regular visits, I think it's more than worth it. I appreciate I have gotten totally lucky and there are no guarantees, but I think a 1 month sub is definitely worth a go.
After 10+ years of punting, this is the kind of natural encounter you will not receive 99% of the time from service providers. But then, punting definitely has its benefits too (less wasted time, more quick/clinical, you don't need to make small talk before/after the act).