Welcome to the site, Dave!

The 7075 will offer almost no difference in rated power over the 1070's amp section - 10W or so isn't going to be audible in and of itself. The 7075 will offer an amp section physically isolated from the more sensitive pre-amp electronics, a larger power supply (for more ably handling transients produced by very dynamic music and movie soundtracks), and a potentially easier upgrade path down the road (keep the amp, replace the "brains"). Plus, if you have any need for a subwoofer, you can get an LFM-2 for free at the moment with the 970/7075 combo.