We have visited CP over 40 times now and would only book executive or higher standard accomodation. We have booked the exclusive villas before and it is worth the money for a special occasion - just lying in the hot tub at midnight under the stars is magical!
The villa is only realistic for 6 adults though as the settee area is not really big enough for 8 adults.
The steam room is a bit disappointing, it's basically a large shower cubicle with a shelf to sit on but the steam works fine.
Warning - at Elveden there is a gas fire so you can't burn logs as there is no open fire.
You HAVE to book a night out at La Sapiniere, it is wonderful and Jose [head waiter] makes you so welcome, there is a pianist playing all night and the restuarant revolves so you get a full view of the lakes and forest from the top of the hotel - a magical, relaxing and sophisticated night out...remember to dress up as there is a dress code [not really suitable for under 10 year olds or those children who wouldn't appreciate real french cuisine].
We loved the experience and I shall book villa 100 [the original luxury villa with it's own private garden] for my husband's 40th.
You should also check out the new 4 bedroom executive villas as they have a games room with pool table, playstation, lcd tv etc.
Have a marvellous time.