I have stayed at Galleria 10 twice. Mikel gets it right. A couple of things to add: The lobby restaurant tends to get overwhelmed at breakfast. It's often hard to get a table quickly and it takes a while before tables are cleaned. The wi-fi on upper floors and at the pool can be dodgy.
It's a 5 minute walk up to Sukhumvit or CIB. Galleria 10 gets very little traffic out front, so if you need a taxi to take you and your luggage to the airport, be prepared to wait 15 or 20 minutes for the bellhops to fetch you a cab.
Don't know if this is important to you, but they do not take IDs of guests at the front desk. While you don't have anything to worry about with girls from CIB or Why Not, you may want to keep this in mind if you bring in a freelancer.
Thanks reacted to oliver17 in Galleria 10 & 12 in Sukhumvit, Bkk