How much typically are these brothels and what kind of service? I'm assuming similar to soho?
Depends on the area I've found. Brothels in the same area will often be competing with one another (therefore offering similar services and prices) or they might even be run by the same people. In the Paddington area covering Edgeware Road and neighbouring streets the going rate last time I checked was £60 for 20 minutes or £80 for 30 minutes. Didn't enquire about hourly rates. You are generally offered a vanilla service - like in Soho. It's also a similar price. A 20 minute punt in Soho is £55, and not double the standard 10 minute rate of £20 since in 20 minutes you're allowed multiple position changes. In Paddington, position changes are included and lots of extras are available (kissing, OWO, etc, etc). These you have to negotiate with the girl in the room, for extra cash, in my experience.
Other places I've found brothels - Covent Garden, Kings Cross and Holborn. Similar rate and service to Paddington area. Since they don't tend to have websites and come and go all the time you're best to phone and discuss what you want, agreeing prices for everything in advance. Never just phone to get the address and turn up. The one time I did this the maid wanted £100 for a short punt with one of her girls and I had to barter.
As you'd expect, in more expensive locations with upmarket hotels - e.g Mayfair - the rates are higher.
This type of punting is probably riskier than seeing an unreviewed girl advertised on AdultWork since at least she has a profile. Any lowlife cunt could put a card in a phonebox and direct random strangers to a location with the sole purpose of robbing them. So be careful.