The IC225 is a generation newer, maybe about 15 years in techology. I prefer the HST but that's strictly personal. I love the British MkIII coach. For all the build-quality issues they had, it was really comfy to ride in a seat or a sleeper.
The 225 is really cool because the locomotives have the traction motors hanging from the body and thus it's sprung weight rather than being axle-mounted unsprung weight. Also the transformer hangs very low - it looks like a fuel tank. A very innovative product. It was one of the last true British electric motors, as they now source their trains from Japan, US, and Germany mostly. As far as I'm aware there is no more BREL staff or anybody fulfilling the role of designing and making mainline trains in the UK anymore as anything more than a satellite of Hitachi or EMD.
I was never keen on the voyager becuase I don't like diesels aboard the car I'm riding in. The only really quiet one was the 170 class Turbostar but I don't love them either.
I've been aboard a LRC coach but never behind the MLW power car as those got the toss long ago. The Montreal-Toronto ride is nice but I wasn't bowled over. Eurostar it aint.
Amtrak is proud to announce a new train to Florida that doesn't stink: The Floaterian. An all-star just like Babe Ruth.