Considering I'm actually a Power Glover and I understand the market here are the real cons.
High Price Ticket, the need for a dedicated software engineer while you are on stage for a good performance, and the lack of wrist movement.

I prefer the Remidi T8 as my Power Glove of choice, its only 159$ on eBay or 399$ MSRP (Compared to 2000 Quid/PoundSterling) plus its easy to switch between MIDI sequences and Macros on stage without having to Use a Web Camera. Here is a video of me on DTUBE using the Remidi T8 in action.

the mimu gloves are nothing like Michael Jacksons gloves either lol