I recall reading about those in PC Gamer; I think the best thing they had to say about them was that it seemed really useful for people with really bad vision because you could set it to vibrate when you passed the cursor over interface elements.
I first heard of haptic-feedback mice like that back in 1999. I was working with haptics at the time.
Back in 2007, I knew of a local company that developed software and grips for an existing very expensive industrial haptic device to be used for games. You would hold it like a gun and it would give you realistic recoil.
I think that something like that would be interesting for gun-play in VR where you would move gun-substitutes around in the air around you. I think faking recoil without haptic feedback would just disorient you in that situation.
But I dunno how recoil would work when you can't attach it firmly to a desk. You would have to use compressed air or something like it.
Was it the Novint Falcon, by any chance? I briefly had one, hoping to use it as a translational hand controller for 6DoF space sims in this age of Elite Dangerous and Star Citizen, but I couldn't get the drivers to work properly. Ended up reselling it.
Only having four buttons was also a limiting factor, but chances are people would be sticking unlicensed "grips" with zero buttons on them anyway, if you catch my drift...
The 3DoF force-feedback could be pretty cool, though. Most FFB devices are inherently 2DoF (joysticks) or 1DoF (racing wheels). For my intended uses, the Z-axis could have dynamically shifted between a "conventional" throttle that holds its position and a centering axis for more fine-tuned forward/reverse acceleration.
Anyway, as for vibrating mice along the lines of the Logitech iFeel and now this thing, it'd be difficult to pull that off without making the vibration move the mouse itself and thus add jitter to your inputs once the sensor picks up that movement. Noise to the signal, if you will. Bad idea. That and rumble motors add weight, which hasn't bothered me on my Logitech G502, but then you've got all those OCN types who act like anything heavier than an old Microsoft WMO is unbearably heavy and would break their wrists.
Rumble motors don't bother me on gamepads because it doesn't throw off the movements on those tiny thumbsticks and triggers so directly, and I admit, the Xbox One "impact triggers" are kinda neat when used properly, like in Forza 6 Apex. And for full-size joysticks, I actually find proper FFB beneficial for maintaining trim (the "spring center" changes as you trim) and flying on the edge of departure in some old WWII warbird. Seriously, try out Rise of Flight or DCS with a MS SideWinder Force-Feedback 2 if you get the chance.
