Matt,
Trevose is rated 65 by Golf Monthly. Golf World, which is generally considered the more accepted and authoritative ratings provider, has it outside ther Top 100 for GB&I.
It maxes out at a flop shot less than 7000 yards and is a regular gost of major amateur events (Brabazon, McGregor etc).
It's a very good course, IMO, and provides good contrast to St Enodoc just a few miles away.
Holes such as 3-5, 9, 14, 16 and 17 are bloody good, IMO and while a few others are somewhat disappointing, there are a lot of strong holes to support the standouts. I also really liked the routing, which keeps the wind shifting and provides a good mix of uphill, downhill and flat shots.