LCOS and DLP are different viewing experience. To me, contrast is a very critical aspect of viewing experience, besides skin tone, black and depth. From a financial perspective, I cannot justify the 2x plus expense, but that is why they sell BMWs and Mazdas (have both). I used the JVC primarily for HD movies while the 3800 for sports and non-HD movies. For the majority, my brother-in-law was happy when he saw the hc3800, very transportable to boot and easy to the wallet. He is retired but I'm still working.
I did not go for a hi-end DLP due to RBE, an annoying factor but not a deal breaker. The other DLP I had in the past was the 720p Benq 8700 plus, but the color was not natural. The Mitsu 4000 DC3's contrast on paper is a step up but reasonable. Never saw the Samsung but I'm sure it's one of the best DLPs out there, based on the 3k plus forum. This hobby, like any others, could get very expensive and addictive.
After going thru about 8-10 DLP and LCD PJs, even my wife noticed the JVC but none of the others impressed her. She only watches in her 42 inch plasma but just as happy w/ her old 27 inch Sony CRT. I'm looking to "upgrade" hers to a Samsung 50 or 58 inch plasma.
One last note, I found OTA free HD channels's sports are better than cable or dish. It's a pretty well kept secret if you can pick up the signal. I love NFL using the Mitsu 3800. It does have the pop.
Good luck and enjoy.