Hi
Funnily enough I had a look myself, my son is 2 and a relatively light sleeper. I met with the owner, as you may have, seemed very nice, knows what is what and obviously has 2 other successful sites.
Personally I did not feel it adequate, purely because there are only 2 children, it is not set up right, not great to have toddlers with the babies, not ideal for development and interaction. I do not feel my child will benefit, it may even set him back. It is really set up as a child minders.
Although it may be perfect for your son as he is only 7 months, and it may be a great place to start him off, he will get full attention and I guess more would have joined in time. It is not the end of the world if you have to move him in six months, but get him used to being away from you for now! at such a young age they adapt and settle easily. It is just hard on us.
Regarding the light sleeping, although distressing for us, it is not a bad thing, I have been here before and in the end it trains them to sleep through more noise, and the team should be have a routine.
If my son were 7 months and I really needed to return to work, I think I would feel more comfortable sending him to Bright stars, being on the doorstep, and literally having that 1 on 1 care.. may be ideal!
I too am still looking at places, I am literally down the road aswell, and that would have been ideal, I was more impressed with the Montessiori in Bush Hill park ( cricket club) hours may not suit you.. but there Ethos is good and from what I hear that really stick to it!
I think it is still early for the one near us, they will need to have more toddlers join before I send my son, good luck, and if I hear of anything or find a place I shall let you know.