Spas in Dubai

Dear Dubai Community, have just been handed a spa project in the Marina in Dubai and am doing some initial research on spas in Dubai before I come out end of the month. It seems that Spas are a dime a dozen in Dubai, mostly asian inspired and with fairly standard menus.
if there are any spa goers on this forum, was wondering which ones you go for and what you think of them? Also, what would you be looking for from a spa? The one we have been asked to design is within one of the residential buildings in The Tallest Block and it seems that there are quite a few of those residential giants that boast of spas - though some deeper digging reveals that it's just a sauna/steam and plunge pool, plus gym and swimming pool.
Would be really grateful for any information and experiences that you would be happy to share. Also of interest is how you find/choose the spas you go for!
Many thanks and greetings from rainy, grey London!
Ian