I've been experimenting with wireless MIDI and in my experience bluetooth has three problems:
- Latency is terrible when a lot of data is being streamed. Probably not an issue with the MF3D, since it only has buttons, but would certainly be a problem if it had knobs or faders.
- The biggy: bluetooth has no notion of MIDI like USB does. That means the only way to get it working is to either use some kind of bluetooth-to-midi bridge program (I've done this) or writing a driver. A driver is the more fool proof version for the end user and is the only real solution for a consumer device, but adds a lot of development, support and maintenance work (ie its an expensive option)
- Adds to the cost of the controller - I imagine DJTT were trying hard to keep the costs down and adding any kind of wireless would definitely have brought the cost up a bit more
The lack of HID compliant MIDI on bluetooth I think is the real deal breaker for bluetooth. The best option, for the end user and for latency, would be to build a USB base station and communicate wirelessly between the controller or base station.