Both use the Reon.

The 886 is extremely well-equipped from a feature standpoint. It is also a pretty darn nice-sounding piece of gear. Will the 997 sound better? Maybe. To my ear, the 990 (without room correction) compares remarkably well to the 885 (with room correction, albeit in a relatively well-behaved room acoustically). The 997 should retain some of the 990's sonic legacy, but add Trinnov. We have to have a chance to hear Trinnov to know just how good it can actually be, how much difference it might truly make.

My guess? Neither choice is a bad one. I expect to go with the 997 in part because my wife has never been a fan of the Onkyo's user interface or its slow signal acquisition times. Going back to an Outlaw should allow her to say farewell to a component she isn't fond of. I'm also curious to hear Trinnov, though.