Personally, one of my favorite brands that I have ever seen and worked with would be the Sim2 projectors. Those guys have got it together as far as solid engineering goes. High quality product, with features like a true pixel-for-pixel PC pass-thru so if you hook up a home theater PC (HTPC) set to 1280x720, the projector doesn't rescale it before dropping the image on the screen.
They didn't skimp on any part of the design and bulbs are rated to EIGHT THOUSAND hours. Hello! Anyone else even coming close to that claim in front projection? Not that I have heard of.
Included is Faroudja image processing as well as the standard H+V optical lens shift.
These guys then put it all together in a classy art-deco styled case instead of your usual beige plastic common. Hello! Anyone for three color choices AND a quality projector? Colors: Gun Metal Gray (standard), Royal Burgundy, and Shiny Silver.
Take a look at
www.projectorcentral.com - and
www.sim2usa.com I have never met anyone who has owned a HT300 who has been upset with that particular projector. It is most definitely designed for a true theater though.
Oh, and if I had a 10-15K budget, it is 100%, positively, the projector that I would buy above all others.
Gotta say, of the two you listed, I'd probably get the Marantz... but I get dealer pricing on that.