So, i have received my 3700. I ran it side by side with 2040 and conclusions are, well, inconclusive to some level but quite expected.
It is indeed a light cannon and it is nice. I am very glad i got this 3700 and not 3100. I really would like to look at 3900 eventually but probably will stop wasting money now.
So, first and foremost - this is a loud projector as well. Its ECO mode is almost silent, it is probably twice quieter than a 2040 but not nearly as silent as expensive Sony or JVC. Even in ECO mode - you can hear it but it is no longer at the level of annoyance like 2040 when i would watch TV late at night at low volume.
High mode, as expected, is still a jet engine. It has a bit of a lower tone than 2040 but still a jet and imho same or lowder than 2040 high mode noise - not OK at all.
Medium mode of 3700 is not as loud as high mode of 2040, it is lower pitch so does not annoy as much but noticable, as projector is mounted right above my seating place. If I would buy this projector initialy i would probably used 35ft cords and moved it to the end of the room as 3000 lumens is a lot.
So, now good parts. Been a light cannon you do not need anything other than ECO mode for 2D pictures. It is as bright as a TV in ECO mode. Black levels are definitely not Sony level but very decent dark, 2040 would make screen definitely greyish tint, this one is i would say almost exactly in the middle in between 2040 black level and area with no light. As i do not have walls painted black it works. So, i would say, black levels are adequate but could have been better.
Now, best part. Optics of this device is on the different level from 2040. Screen is perfectly sharp corner to corner and focus gives almost perfect perceived contrast. LCD panel adjustment is a deal braker - after 10 min of doing that process i got image i wanted and could not get from 2040, ever. Again, i speak about perception - it is perceived much sharper and has much better local contrast, no greyish content in lines.
So, working mode for now is set to cinema ECO mode and for 3D it is medium lamp. 3D on medium 3700 lamp is twice brighter at least compared to 2040.
If it is worth 2x price of a 2040 - i am not sure at all. Most of differences are at the level that i am sure my wife or kids would not even notice. interpolation, fine processing, all settings seem to work same but a little bit better and menu got additional adjustments and levers to pull. I would not be very surprised to find out eventually that 2040 got same processor board with same exact code and just turned off features. go figure.
But, lens is indeed of a different class. if you move your nose 2ft away from a 100" screen - you do see it as clear as a day. Go back to a seating position 12" away from the screen, and, well, you know.
Vertical and horizontal lens shift is nice, very nice. Only problem - i already spent half a day finding exact location to drill into the ceiling to hang old projector in a dead optical center of the screen.
So, i would say, for $1500 from B&H - if it not your last money, it gives you a very good if not best i saw to the date 3D projector. As 3D content is almost exclusively the stuff we watch with kids - 3700 stays.
If all you want is 2D content - i would not be so sure. black levels are decent, better than on $650 2040, but are they $900 better? I seriously doubt it. But, next device to top 3700 would be Sony 45ES and this is an another $500 on top of a 3700 price, so, decide for yourself.
Device came with very well set colors in all modes. Slider to set skin tones is very useful, again, definitely a feature artificially taken away from the 2040 menu. Overall i am pleased and if wife will not find out
- i intend to keep this one. Need to sell 2040 now.