I use this with a peavey 6505+ and it really works well! The practicality of a 2x12 for me is the storage and more space for transportation but I really wouldn't look to get the 4x12 when i've got this.
Being wider than the open back, this closed back version really does have more of a punch to it.
Also if you're not as keen on this because the 4x12 means that you you can hear it better and you think the 4x12 looks better just whack one of these on top of the flight case and see/hear it then ;)
The Orange PPC212 Open Back is an awesome cab. Built with thick plywood and loaded with a pair of Celestion Vintage 30s, I'd say it's an industry standard 2x12. At first it sounded a little harsh, but over time the breaking in of the V30s has proved to be good for the tone. I've used it with my Orange Dark Terror and Jet City 100HDM and they've both sounded good with the cab.