I have had 2 rounds with Create, who have clinics in Wimbledon and St Pauls. Their approach is low-drug and natural, and they treat patients which other clinics have turned away (lots of other clinics won't treat you if you have low AMH or FSH over 12), which means their published rates look low, but if you go and see them, they can give you their success rates for women in your category.
We approached 4 clinics originally (including the Lister and ARGC) and were impressed with the approach of Create, and also the clinical staff there.
The bad points are that the admin is a bit disorganised, and you can often be kept waiting for appointments, but compared to friends who have used other clinics, it isn't as bad as others! The low-drug/natural approach also means it costs less than other clinics, but is still brand new and state of the art, so it doens't feel 'budget'.
They have regular open evenings, where you get a free consult with one of their doctors, so if you take your results in with you, they'll talk you through the treatment plan that might suit best, before you have to part with any money.
You are also given the mobile number of your consultant, and an out-of-hours emergency mobile number for the duration of your treatment, by the way...