A positive update to this thread.
Decided to go with Andrew Sinclair at Bristol & Wessex. Had just under 3hrs in their excellent simulator including first attempts at RNAV approaches, 1.5hrs in a very nice G1000 equipped Cessna 172, followed by revalidation flight. Friendly, professional instruction and the added benefit of flying at a busy commercial airport so that you are operating in a realistic situation.
Bonus was an examiner who went beyond 'testing' and looked to extend my skill set.