I saw Tommy at a Tamworth festival Music Awards concert about 5 years ago, jamming with Albert Lee and a (then) young Australian guitarist called Rod McCormack. They traded licks for about 15 minutes, and you couldn't pick the difference in ability, although styles varied slightly. Incidentally, Rod won the National Banjo Championship a couple of times - he is the best 5-string banjo player I have ever heard - bar none, including the likes of John Hickman.
Another great bluegrass guitarist is Andrew Clermont, who has toured the USA I believe. He has been National flatpick and fiddle champion numerous times. He is a pretty mean mandolin player as well!