Yes, I don't like the separate chassis and requirements to have another set of ICs... the trafos are very small, probably easy to fit inside many components. They are relatively expensive though, so most mfg'ers stay away but if you want to drive a balanced amp with a SE tube preamp it seems like the best way to do it to me, and also eliminates the possibility of ground noise issues. They can be paralleled with XLR inputs in a couple different ways, since the trafos are very transparent right now I have the XLR and RCA ins run in parallel into the trafo primaries with no switch, you just can't have an RCA and XLR cable plugged in at the same time. A switch would allow the XLR in to bypass the trafo, but now there's a switch.
Most class D amps are balanced, it doesn't matter to me so much as I mostly value their amazing grip on woofers. The NC500s are FANTASTIC for active bass duties!