Yes, I've tried the (now discontinued) Crucianelli 12x4 48 bass.
Thankfully they do now have a workable air button and some nice touches like the grippy bit behind the fingerboard. Another plus point is the weight as they are incredibly light.
On the downside, a 3 voice (they are 2 voice) would probably give better balance with the bass and they're a bit chinesey in places. Also the RH keyboard is very slightly stepped with musroom buttons on stalks rather than a totally flat keyboard with buttons going down holes, but as it turned out this didn't present any problems.
If you want something light, with all the basses, that doesn't need hospital treatment before being playable, then it's worth a look.
