I've seen people wondering if they should get the powered or un-powered toaster.
One huge perk of having the powered version is that I can keep a 1x12" right next to me while tracking and use it at low volumes to get feedback and sustain. I still record into Logic using the Kemper's direct outs so I don't have to worry about bleed or use headphones.
The guitar responds so much better when the strings get some sympathetic vibrations, and it doesn't take much to make a huge difference, especially when using a hollow body guitar like a Gretsch Falcon.
Now I just dial up the monitor volume control on the Kemper when I want more sustain. It's also a great way to quickly play ideas for a client listening over the phone while jamming along to the track without having to set up the DAW to input monitor.
I've never been able to get any musical feedback from the studio monitors this way and they'd have to be cranked. With a 1x12" right next to me it's super easy and sounds great!