Hate when wife says yes.....

I've got the A15.2, but i haven't used the line out yet for a possible sub but the amp itself is great for the money.
also in austin area as well

you can actually order the Music hall from Audio Systems in town, but they don't keep them in-stock.

For what it's worth, I'm enjoying my original Decco in the office as I type this, driving Era 4 speakers. My Mac's playing lossless files and it sounds great to me. The Decco's are pretty as well.

Full disclosure, I had a problem with my unit and it was replaced and about a year later another problem occurred. It was repaired gratis other than shipping to Peachtree.

But the combo of SS with a tube does make even compressed files sound good.

If your wife is giving you a present, do you really want to make it hard for her?

i'm running Ascend Acoustics Sierra-1s
i get plenty of bass response, and while i've considered integrating a sub. i don't think one is needed.. however i am running my setup in a fairly small room. 10X14 feet Max.

i'm not surprised you wanted more from the cambridge its a receiver with only 40wpc though that is more than your current NAD. If i hadn't gone with the 15.2 i more likely would have gone with one of their NAD integrated amps they have at audio systems... I went with the Music Hall because i like to run vinyl from time to time, but most of my music is done from my home music server using FLAC using my laptop as the source attached to a HRT Music Streamer II.

if you want to add a sub to the MH you could always find a sub with a remote, while not common is more and more available.

also you might want to look at the HK 3490 its a 2 channel receiver with 120wpc that is high current so can also run 4ohm speakers. its has a dual subwoofer out and gets good reviews. i also considered it myself but never got around to auditioning it somewhere.
if price is a consideration .. the HK should be the cheapest of all your considering and it does have an onboard DAC for running optical.

wow I didn't realize emotiva had recently put out an integrated amp.. if you only have one input it seems like a very nice option especially for the price, doesn't seem to have a remote though.

I understand on the size of the HK that was one of my issues with it as well as to why i didn't end up auditioning it.

the Decco 2 is a nice piece as well, but doesn't have a ton of power and is not really high current, so if you upgrade to 4ohm speakers you might have issues depending on how loud you play it. If its USB dac had asynchronous processing i might have gone that route as a possible dac/preamp.