I've used the Excel - it does indeed chomp everything we've thrown at it and is the quietest disposer I've ever heard running (although it's become slightly noisier over a few years. I've also used the entry-level Evolution model called the Compact which despite its smaller size is almost as quiet, certainly less of a difference than the in-store demos set up in some stores. The Pro versions are typically sold at plumbing suppliers, not sure of the differences offhand between the pro and non-pro models.

My understanding was the Excel uses undercutters to pretty much decimate anything you can fit in the chamber. The real expensive Viking does also. The other lines/models do not have undercutters.

I'm not 100% clear on what the undercutters do differently, but they are soppsed to be the best. I'm still debating about spending for the Excel. It's such a small increase in budget compared to the total project, but if I spend an extra hundred or few on each item it's going to really add up!

If things have changed, I'd love to hear what's what. So much of the technical GD stuff just made my eyes cross, like lighting plans do!