I have two BMA G3's in my RV8.
For me, they have worked fine, but there are a few bugs that are beign worked on. In the mean time, I have used them for about 130 hours and believe they work at least as well as the other EFIS out there, for similar prices.
I chose them because they looked the nicest, to me.
Because thaty had an internal moving mao GPS and you didn't have to buy a bunch of extra stuff if you wanted to see OAT or magnetic heading. (Down loading updates to the database is simple, as long as you have a laptop to plug in at the plane.)
They offered an autopilot, which I purchased and it works pretty darn good!
The units were pretty easy to install, but you do spend a lot of time soldering up connectors. If you are good at soldering, then your trouble shooting should be minimal.
As far as support is concerned, I would say it is probably as good as anywhere else, once the product is delivered. Their delivery schedules are way off! They are also slow in delivering updates to correct bugs. (For example, release 2.7 for the G3s has been promised for several months, but still isn't available.) But, the bugs aren't that big of a deal, since almost all of the items in the G3 work just fine.
My advice to anyone looking at the BMA EFIS is that if you want something plug and play, look at Dynon, GRT or Chelton, but get ready to ante up extra bucks and don't expect much in the way of updated software. If you don't mind fiddling around with the installation and would like updated software applications to become available over time, which add new features, then you should be pretty happy with BMA. Also BMA offers the GPS as an internal unit for the same price.
Overall, I'm happy with mine, but it would be nice to have the Gen 4 models. Oh, well......