My system had been fairly stable for the past few years, but I just upgraded my processor from the Marantz AV8801 to the Marantz AV8805. I currently use an NHT Power 5 amp that I’ve had for about the last 10 years. I knew the concerns of class D amps before I made the purchase, but I had young babies at home and I was looking for something that I could easily put behind closed glass doors and not worry about heat. The NHT amp was perfect in that regard and I’ve been happy despite it sounding a tad harsh. I've found that over the last 10 year the amount of time that I sit down and really listen to music has become less and less frequent. Part of that could be that I never loved the way things sounded for long listening sessions. I will say that I’ve been listening to 2.1 more in the past couple of weeks since I’ve added the 8805. I’m running NHT Classic 4s as mains, with and NHT 3 Center and NHT in-ceilings as the surrounds. To handle the .1 portion of my 5.1 system I use and SVS Ultra 13. I plan to upgrade the speakers one day, but would like to wait until the kids and their friends are older to limit the chances of collateral damage to the speakers. I’m thinking of something like the Focal Kanta No2 as the mains. I wasn’t planning on making any other changes for now, but found myself flipping through the latest Stereophile on a flight a week ago and noticed that the Classé Sigma Amp5 is currently 50% off. Sorry for the long into, but here is my question. Would the Classé be a noticeable improvement over my NHT amp?