I have the Hogwarts set, mostly for the novelty of a UK-style excursion train amongst my fleet (There was a UK steamer whose name escapes me at the moment that toured the US in the 1970's). I have extended my HE out to 9 cars in order to mimic the look of the excursion trains operated in the UK.
I also have a pair of the TRAXX electrics play-acting as a freight electrification demonstrator. If any of the European high-speed trainsets were released in O' Id go for one, even though it would strain my storage capability.
---PCJ