I grabbed one of these along with a DaVinci Resolve license in the currently available bundle, and as someone who HATES using mouse and keyboard to navigate timelines and drag things around, this was a no-brainer, as I basically got it for free with the license.
The keys are great for someone who needs forever to learn keyboard shortcuts, but the jog wheel is the big deal here; without even switching mode, you can flick it up to several times normal playback speed (it has nice inertia and smooth bearings), to get to the general area, grab it, and instantly deal in individual frames. And absolute game-changer in speed and comfort. A mouse cannot even remotely compare to this, no matter how you use it.
Only downside is that there's no backlighting in the keys, which is somewhat problematic when working in a dark room. (I'll probably just install a soft spotlight in the ceiling, as this is not the only device I have with this problem.)
I suppose one could also have wished for more extensive support outside of the Cut page in Resolve, but then again, how general can you make an input device before defeating the whole purpose of a dedicated tool for a specific job? As someone who just moved to Resolve (no time to develop bad habits ;-) ), I rather like the lean and mean Cut page, and I like how this dedicated controller makes that page even more effective and comfortable to use. IMHO, the very point of a special tool is to do one job really well, and I believe the Speed Editor delivers on that.