Hi Sandy, I have a Noblex 150; don't think it's a U model because the slow shutter speed module doesn't fit. Anyway, it has the sharpest and contrastiest lens that I own, better than the 35mm Nikkors and Mamiya TLR lenses. It is extremely sharp. My exposures are all right on. I do mostly sunny 16 stuff, and in lower light situations I meter with my 35 Nikkor and set accordingly.
It does have some mechanical issues. If you don't follow the film loading instructions to a T, you may have overlapping images. And now I get overlapping images sometimes when I do follow the instructions. So I'm going to send away for service. And even with overlapping images, sometimes the negatives are usable.
You should be able to find filters on ebay. And there was a guy in Holland who made them; can't remember his name.
The camera will take some getting used to, as it is extremely panoramic. Tilt the camera up or down slightly, and close (5-10 meters) horizontal lines bend in the middle. And that's not necessarily a bad thing, but be aware that it's there.
I've had fun with mine, although it is not my primary camera. I do know a couple of other folks who use it more than I do, and they do very nice work.
Good luck, and have fun.