Hi. I have been a long time nuprime user. With the improvements in your lineup, I am having a hard time deciding on which amp to upgrade to. Currently I use the MCX-2 and want to keep all the wonderful aspects of this amp, but with increased detail (not edginess) and a more extended high end. I like that it has enough power and control so that the bass is tuneful, well controlled and seemingly limitless power. It has a slight warmth and sweetness, but not excessive. Reasonably wide and deep soundstage, but not quite as layered or specific as others. A nice to have would be a better layered soundstage, but I would be fine keeping the same as now. Previously I tried a IDA-8, which had all the characteristics of the MCX-2 but limited dynamics/power. ST-10 was too edgy and brittle on the top end. ST-9 was too warm and lacked detail. The amps that sound interesting are the Evo STA SE, the IA-9XG, IDA-9, and the fusion 2X. Previously I simply bought all the amps and tried them one at a time, but that gets expensive, so I wanted an educated opinion on which one you think would work for what I am looking for. I have been trying other brands of class D and while they excel in one area or the other, they lack the musical involvement that my MCX-2 has. Thanks.
Based on what you wrote above, I suspect we share some similar likes and dislikes in amp characteristics. Like you, I purchased the IDA-8; IDA-16; ST-10; EVO STA, and the EVO STA-SE. The IDA-8 was excellent in a small room with reasonably efficient 2-way speakers (86dB/8 ohm). I gave it to my son as a house warming gift. I found the ST-10 and IDA-16 too edgy and/or bright as well. For me, both the EVO STA and EVO STA-SE are winners. I bought the EVO STA a few years ago, and I have happily used it as my summer/hot weather amp or when my tube gear misbehaves. I've powered 2-way and 3-way standmount speakers and 3-way floorstanders with it, and it has done a great job of powering them. It's a warm (but not syrupy) sounding amp that pairs well with my SS and tube preamps, and even with my DAC w/volume control.
When it came time for me to buy a SS amp for my vacation home, experience had taught me that I needed a serious power to make my 82.5dB 2-ways sing. I was on the verge of buying a pair of the STA-9x to use as mono amps when both John and Jason grabbed me; threw me to the ground, and threatened me with bodily harm unless I relented and chose the new EVO STA-SE instead. [
In my old age it's possible I mis-remembered a part of the selection process. 
] Anyway, I did choose the EVO STA-SE, and I have been delighted with its performance and sound these past 5 months. It's paired with a Holo Audio Spring3 KTE and either a CD player or Tidal via my laptop.
I cannot tell you how the EVO STA and EVO STA-SE compare because they were never under the same roof nor have they powered similar gear. I can say that I'm happy with each one, and that I have no intention of selling either. I may yet upgrade the EVO STA to SE level as Jason has made it very affordable to do so.
Should you find yourself wandering near the Willamette Valley in Oregon....shoot me a PM. If I'm home and not wearing myself out chasing my 2-year old grandson, you're welcome to come listen to some tunes.
Michael
