If you are familiar with open source software than you are familiar with Open Tx. This sort of software is not new, and is continually under development and revised frequently. You could say it is "Crowd Tested" by the hundreds of people using it every day and reporting any problems they discover which are then solved with the next revision. You can choose to install older versions of the software that have been proven over time by thousands of users, or you can install the latest version which may or may not be as bug free as the older version.
Microsoft and Apple both use the same system as do thousands of software manufacturers. They test new software as best they can, distibute a few copies to some beta testers for further testing and then release a version they believe to be stable.
I think the Open Tx software is ultimately subjected to much more intensive testing by it's enthusiastic users than anything produced by the mainstream radio companies.
FrSky is not a new company and neither is the Taranis. Open Tx is not new either. All have been around for years. I have been flying my Taranis for probably 2-1/2 years and it been out for sometime before I bought it. I have updated the software once and am several versions behind but see no need to upgrade as the radio has been absolutely flawless for me.
One of the things I really like is the price of parts and accessories. I recently broke my transmitter antenna, bought the part for about $4.00 and replaced it myself. As a matter of fact I hought 2 antennas because they were so cheap, now I have a spare. Virtually any part is readily available, cheap to buy, and can be installed by the user. No need to send your radio in to the manufacturer or distributor and pay for repairs. Do it yourself.