In fact the suites on Marina are beautiful - and i would bet they compare very favorably to Regent suites.
I just put up a pictorial of the suites - most of the top pics are from the 2000 sq ft owners suite.
CruiseMates Cruise Community and Forums - Paul Motter's Album: Marina Suites
The "Penthouse" on Marina is what most peiople would call a mini-suite - it is nicer than a verandah cabin, but just the next step up.
The Vista suites are very nice and the owner's suite is over the top in self indulgence - no one could be dissastisfied there.