I can offer some Newmarket intel as I drive Davis nearly every day to/from work. I'm new to this board but long time member of the other. Here is what I know,
Ocean Spa on Vincent is a big house on edge of residential area. Never been - but checked it out from outside. I didn't even know it had a name. I wasn't comfortable going in with the houses around. I understand it is a FS type spot and I would think if LE ever decide to crack down, this will be the first spot that gets hit. But just a hunch.
There is a new Ocean wellness spa just west of that spot right on Davis in the same shitty little plaza with the tat parlour. Haven't visitied it.
Urban retreat as mentioned has been around 4/5 years. Used to see the owner Cici a lot. She was cute and open. More Semi Legit. I've been a few times last year but always for basic service. Nothing special that I've encountered. Owner Cici I think still owns it but spends most time down in Pickering area with another spa.
Aylaine is Yonge Spa to me - across street from value village. Been a few times. I had basic service but there were hints that more was on the table. I hate that there is a kids play place two units down so avoid it.
Brand new spot on Davis just a hair east of Yonge is Master Therapy. Sign on street says 25 bucks for 30 min so I tried. Very clean, bright spa. Pretty sure very legit but who knows. When I visited there were a couple of younger, cute attendants but unfortunately they gave me a short haired older lady who was their house 'rmt'. didn't want rmt, but whatever. It was quite good...but nothing close to a HE. Btw, the 25 bucks/50 for hour doesnt include tax.
May Blossom I have visited about 50 times. Mostly blue balls service, but a few offer more. I usually go when they advertise the 40 dollar 45 min specials.