You see very few references to this particular model. I searched extensively to compare the two as I am also interested in that model because it looks very close to 49TX. At least from my readings I find that there are three noteworthy differences:
1. 49TX has an extra sharc processor and individual ADCs for each channel.
2. 49TX has an "advanced" version of MCACC and the parameters are manually adjustable after the automatic adjustment.
3. Has a better(?) and bigger touchscreen LCD remote.
Of course, 49TX has also 2 extra digital inputs. Ohter than that the feature set is similar. Both are THX ultra2, have the same amplifier section rated at same wattage, have RF demod built in, have RS 232 serial port for future software upgradeability(!), etc.etc.
Having said that, I have never read anyone doing a direct comparison of the two and deciding on either one. Doesn't mean it hasn't happened but just that I haven't read anything yet. Most reports are from people owning 49TX including our own Robert George. If you see the schematic of the two you see some extra processing power in 49TX. Whether it relates to a direct sound quality difference today or expandability tomorrow or a bit of both, I don't know. I wish I did as these are among my three finalists along with HK 8000 as my Outlaw 950 may be a long while in coming. I reserved only on the 25th December.
another difference between the two is that the 49tx uses a special video processing feature that upsamples all of your video sources to component output.