Matt - I would imagine that you've probably lost interest in this thread, but in case you're still following, I wanted to add my own thoughts.
There's been some interesting discussion here, but as a N800 owner I thought it might be helpful to share my own experience.
First of all, I should note that my 800s are a previous generation, but I've heard them all and the differences between model years is very slight.
One thing that hasn't been directly addressed here is the fact that (at least in my case) there's really only one main reason why someone would buy a pair of N800s - and that is that we want to as accurately as possible replicate the exact sound that was created in the Abbey Roads mastering studios. I auditioned many other speakers and actually preferred the sound of some others (Wilsons, for example) but at the end of the day, the goal of reproducing the sound that the mastering engineers intended was my focus.
With that in mind, you almost HAVE to power these with Classe monos if you want to achieve that goal.
However - I went in a COMPLETELY different direction after hearing at least a half dozen different amps behind these beasts and here's what I ended up doing and why:
I'm using my 800s as part of a 2CH and HT setup (with N803s as surrounds) and therefor I needed a multi-channel setup with plenty of power.
What I ended up with is a 7 Channel Class D amp from D-Sonic (Dennis Deacon's company) which is based around 7 B&O licensed ASP-1000 Ice Power units.
Each channel puts out ~1000W at 4 ohms and is stable down to 2ohms which isn't outside the realm of what the 800s can reach.
In my setup, I have each 800 bi-amped with 2 ASP-1000s per speaker.
While I loved the sound of the 800s with the Classe, the 800s being driven with this amp takes them to an entirely different level.
In particular, the instantaneous modulation that this amp provides enables you to drive the 800s at any level and the only difference that your volume control makes is simply that - It changes the SIZE of the image. Even at levels where your ears might be bleeding, you can literally have a conversation with the person next to you in a normal voice - it's something that I couldn't say for the Classe's
Also- (sorry Bo) you will have absolute control over the size and depth of the soundstage - In fact at higher levels, the soundstage can easily exceed the room size by a large margin if you wish.
Sorry for the long-winded reply, but wanted to at least offer up another perspective.
If your goal is to reproduce what the studio engineers at Abbey Road intended, then the Classe's are your only option.
If, however, you want to drive these beasts to their fullest, have a look at the Class D option - Having listened to the 800s with this setup, I couldn't possibly consider driving them with anything else and being satisfied at this point- In fact, I can't imagine why any 800 owner would consider powering them with any amp that can't deliver at least 1000W at 4ohms.
My $.02
Take care and congratulations
Greg