Hey, nice!
I'm a HUGE fan of APC's battery backup UPS units! Got a J15BLK and J35B going myself. Plan on adding an S15BLK for the theater later this year
I've had the J15BLK for about 5 years now and the battery finally went on it earlier this year. I had the battery kicking in fairly often with the sensitivity on high, so that probably contributed to the battery giving up the ghost - although it was well after the expected life for APC's batteries anyway.
Wasn't too bad of a price buying a replacement battery and swapping them out is dead simple. Don't even have to unplug the unit (although I did, just to be extra careful

).
I was eyeing a TX-NR3009 myself, but I think the new TX-NR818 will fit my needs. I'll be running separate amplification for at least the front 3 speakers anyway, so I'm mostly after features, which I think the 818 will do just fine for me!
I like Onkyo's higher end units. They're identical to the Integra branded ones, and those are very popular with custom installers, so if they were constantly causing problems like all the Onkyo alarmists would have you believe, there's just no way Integra could remain so popular. Onkyo did have a recall last year - I think it was mostly 809 units. So it does seem they had a bad bunch of parts at some point. That always hurts a brand. But I don't paint an entire brand as "bad" for one bad model or one unlucky batch of boards from an OEM. And the x009 high end models especially seem pretty darn good to me.
So that's some nice kit ya got there!

Congrats!