You'll find a few comments from me here;
http://www.flyertalk.com/forum/marri...hlight=Preston

I stayed at this Marriott for about 2 years, but that was 2 years ago so my views might be slightly out of date. There isn't a lounge. However in return the hotel gave platinum/gold members a free breakfast in the hotel restaurant (full English breakfast, very good including an egg chef who cooks in front of you). I think you'll enjoy it.

The hotel itself was refurbished in ~2009 so the rooms should still be reasonably nice, and all the public facing areas were upgraded to look pretty nice.

Just let me know if you have any other questions.