Hi, if you have a 11s1 or 11s2 then with a new bulb they are rated at 850 lumens, if you have the 15s1 then it is rated slightly higher at 1000 lumens. Once calbirated, the lumen output is probably less and bulb aging will cut that number down further.
If brightness is a concern then the Sim2 M.150 might be worth looking at, Sim2 re-rengineered how the LEDs are used to produce more lumens than the first generation models. The reviews tend to say that it measures brighter than other LED models and even if it doesn't quite reach 1000 calibrated lumens, it looks as bright, if not brighter than a bulb based model. It is darkchip4 DLP based so should have the same sharpness that your used to from your Marantz. I am sure Sim2 didn't skimp on the lens either.
The only potential issue that I have heard of is the fan noise that has supposedly been corrected in the latest firmware. Apart from that, it seems to be reference level performance. I would definitely try to get a demo the M150 and possibly of one of the earlier generation models, you may find that they 'look' bright enough even if the lumen figures don't match.
Heres a review of the M150:
For the same money you could get a 3 chip DLP but obviously it won't have the advantages of LED and won't be quite as razor sharp as a single chip. Some of the newer models still seem to be plenty sharp though and if your not interested in spending $20k can be found for a lot less used.
There is the Sony VW1000 which is plenty bright, from all acounts it can resolve detail at a very high level and higher contrast numbers. I am sure it has a different 'look' to DLP but I think that is going to come down to personal preference as much as anything else.
Of course, we are only one month away from CEDIA and there will probably be some new models announced. Although the VW1000 will apparently be Sony's flagship model for a while