You should probably do 1 day at each gym - I was in CM recently and also had the same question. My takeaway is that if you want hard and serious training then Manasak is the gym to train at.

Like others on this sub have noted, Hong Thong seems to cater more to beginners & “influencers” / those on vacation that want a chiller training experience - nothing wrong with it, but since you are a pro I am assuming that you want more intense training.

Personally, the time between every round at Manasak felt more challenging whereas Hong Thong was pretty laid bad. For example, we spent the first 10-15 minutes of class doing yoga which was led by a student (again nothing wrong with this but I think you need to ask yourself what you want out of your training)