I will be moving from a HD-950 to the X75R in the next few weeks, but I was kind of forced. I had two HD-950s fail due to optical block issues or I would not be upgrading. Based on what I have come up with it should be a nice upgrade considering E-shift (4k lite), new bulb and power supply (reduced dimming and longer life/increased lumen output), and 3D with RF emitter and RF glasses support. I am considering 3d a completely free bonus as I am not all that interested and have not had a chance to see JVC 3D as of yet. There seems to have been allot of debate as to weather it sucks or not, so considering it a "freebie" makes expectations low, therefore less disappointing if not amazing.
I do however have a friend that has had many projectors and he really enjoys his X70. I just haven't had time to get over to his place to see it.
Perhaps you can find a retailer that has some of the new offerings from JVC on display? In the mean time I will return with any of my findings if I get my X75R soon