I have been watching the 990 thread and now that the most vexing problems appear to be solved by the new firmware I am ready to order a 990. I'm undecided re 7500 vs 7125. I currently have a 1050 with which I very happy. But, I'm seduced by "big iron." I have room on my shelf for a 7500, but I'm concerned by its 81 lbs. I will ask the cabinet maker about the weight problem.
I have a 6.1 setup using Mirage speakers (mains are OM-9) all around. If I buy a 7500, I will lose the rear channel. If I buy a 7125, I'm not sure what to do with the rear channel. I built the room around 6.1 and all the wires are behind dry wall. I don't want to open the celing to add a new rear speaker. Any suggestions about amp choice and what to do about the rear channel?
I have a Hsu TN1220 sub which is currently driven by a Hsu 250W amp. I have a hum (60 cycle) problem and will replace the Hsu amp with a 2200 monobloc, if it will drive the Hsu.
Thanks in advance for the advice.

Having the 7125 does not require you to add a seventh speaker - you can leave one channel unused, and if the 1050's been driving your Mirages well I suspect that the 7125 would be plenty of power. (Or you could use the single existing speaker wire as a pull string for a pair of new wires if you wanted to make the move to 7.1... )

Or, you could go with the 7500 and pick up a mono amp for the 6, or a stereo amp (or 2 monos) for 6 and 7. I went the latter and am quite happy.

Keep in mind that the 990 does not allow you to configure the unit for only one rear speaker. This was something I had hoped they would have corrected in the firmware upgrade, but they did not. As they told me you just have to use modes like NEO-6, but it sucks that you can not use Dolby PLIIx. Well you can but there could be something missing.

I guess I will have to build something to mix the two rear channels before sending the output to the amp.

Thanks to all. I will go with the 7125.
What about the 2200 with my TN1220? I am certain the hum source is the Hsu amp and will replace it.