FBSM is a speciality of mine and I prefer it to punting (there I said it!)
That advert (esp) Backpage one suggests extras are on offer. But, unless you have a firm recommendation be prepared for a case of WSWS (Will She, Won't She) and YMMV. Since the recent policy changes on Gumtree came into effect, seeking out a specialist offering extras isn't as straight forward.
I'd be more inclined to check the relevant sections on VivaStreet, where you often get to see a picture.
I went to see a Sensual Sandra (Glasgow) offering a Tantric massage, but for me it was crap as I was keen for a TANTRIC massage (ie prolonged climax / edging, etc) and what I got was a shit back rub and a fast and furious knuckle shuffle.
I really like Middle Aged Asian Ladies when it comes to massage, as they often give a proper firm therapeutic massage followed by excellent HR with great skills.
I must admit, I've never tried a 4 hand massage, but as long as the HR/HE isn't rushed and they try to edge you...all good. Never like it when they flip you over and just start right away. Much better with a build up..
PM me for me details