i read Mike's website a couple of times a week, it seems very informative and he does seem to put people on fish, including a lot of first timers which is not easy to do.
imho a guide on a chalkstream is different to other streams - he knows actually which spot is likely to hold fish, which weedbed has a 'slot' under it etc and where you need to position yourself for the cast and that's pretty much it, the rest is up to the casting ability of the sport and the guide plays statues until he's called to net (a lot like Salmon Ghillies).
freestone guides are more into adjusting the set up, watching the drifts, watching the hatches etc while you're fishing, changing flies and drifts until you hit paydirt - a lot more interactive imho.
judging by his book, i think Mike knows his stuff.
just my .02