We've also stayed at all three Center Parcs ( Elveden twice partly due to it only being an hour's drive from here) and once at Oasis.
My favourite was Longleat - it is set in lovely countryside and is so spacious, you can still get that feeling of solitude which you cannot get in the others - particularly Elveden has more villas in less space. There are also plenty of places of interest outside the parc to visit.
I would not go back to Oasis again ( taken over by Center Parcs now aren't they?) although I thought their villas were very good I prefer the overall style of Center Parcs - I would go back to Longleat.
I don't cycle at home at all but I enjoy it at Center Parcs as it is a car free environment except on change over days. Longleat is more challenging as it has some very hilly places but there are still plenty of places where you can cycle that are flat or manageable. We have taken the boys bikes with us and hired bikes for ourselves - you can save money by bringing your own bikes.
You can spend quite a bit extra if you eat in the restaurants all the time and you pat for each activity apart from the swimmimg paradise, but you do get a reasonably equipped kitchen if you want to do your own cooking.
Also, we did have a jacuzzi in the Eleveden villas even though they weren't executive.
Do you have their brochure as it lists all the facilities an accommodation at each site? Just in case you don't, their website is at
www.centerparcs.co.uk and that may have their brochure line or you could call 08705 200 300 which is their reservation line.
Hilary, I seem to remember that at Longleat which was our most recent visit to a CP, the beds were already made up! I agree with you , that it's is usually a major hassle but we were pleased to find that it had been done for us.
You can hire towels at an extra cost but we usuall take our own...... there's never enough!! ( I also take extra tea-towels as the one they give for a week is not enough.)
Another thing I just remembered - I found the beds very hard at Oasis and I found it too challenging to bike there!!