So if you sign up to the beta can you now use the features for free unlimited or is it on a time limit where you're on the beta for 1 month or 1 year etc?
Bit confused why anyone would pay when you can just sign up to the beta for free
I must be missing something?
First off, you have to apply to the developers to participate in their beta programme. This is conditional on you downloading a full diagnostic from your car and agreeing to upload it to their severs. They then provide you with 90 days access to the beta. There is a precondition that you test the new features for them and provide feedback - but there is no fixed requirement to do so. I haven't and I was granted a second 90 day extension to the first beta.
Obviously if you choose to test changing an option which is still in beta testing and it messes up the ECU on your car requiring a factory reset or a trip to the dealer, than that's the trade-off and the risk you take. But as I have said, beta options are shown in yellow, so if you simply avoid using those and stick to the tried and tested customisations there shouldn't be an issue - and it costs you nothing beyond whatever you originally paid for the Carista dongle.
I experimented with different percentage volumes of the sound akuator but eventually settled on turning it off entirely. I also enabled Scandinavian rear DRLs, setting the lane change indicators to blink 4 times instead of 3 and a few other tweaks I've documented elsewhere on here in my Carista thread. I still have time left on the beta but there isn't anything else I particularly want to change. Once it expires, I'll just leave alone. In six months time if I have something I feel compelled to change, I will then request another beta extension or decide whether the item I want to change is worth an additional fee.
If you're someone who will be changing options weekly or even monthly then it will likely be more cost-effective to use ODB11. On the other hand, if you're like me and just wanted to make a few tweaks spending the least amount of money possible, then I paid £15 for the dongle and haven't paid a penny since. I've made all the changes I am interested in so it's job done. So for me, it wasn't worth £45 or whatever ODB11 costs these days but it may be for others. Horses for courses.