I have, twice infact (the second time only so I could get the tests I wanted) and wasn't massively impressed. Although take that with a pinch of salt as I'm very sick.
Nice guy, more about fitness I felt and probably good for a tune up, rather than healing chronic health issues. His articles on candida and adrenal fatigue were really interesting (was it these that got you interested?) and suggested a knowledge capable of balancing the 2. The reality however was nothing you hadn't heard before. Candida -> low carb + antifungals. Adrenal fatigue (based on an ASI) -> licorice, glandulars etc.