I've been running the T8 for a while now. The reason I grabbed it was because of the appealing price for me. It has its benefits, which have already been mentioned, and it definitely has its flaws. Full disclosure - I have been speaking with the manufacturer on a different product for the 4R, and I have a personal and great relationship with them, but I'm also brutally honest with them when I see issues arise.
I run YouTube premium 99% of the time (ability to save playlists offline). I run Waze when I have no idea where I am or on long road trips. That is literally it. I don't want any of my text messages or phone data going to the unit (call me paranoid). I haven't and don't run into the issues (slow, random power downs) that multiple people have been complaining about. I have heard when people reach out to the manufacturer, the respond very quickly with updates, things to try, etc. There is an issue with the existing T8 where the time and default radio station don't sync up - the manufacturer released a video recently on how to fix it, but it requires you take apart the unit to snip a connection. So, it sounds like they are working to make things better. Should you have to pay $475-$500 and have to do this type of stuff? No, not by any means.
I got the Apple CarPlay kit but was not a fan because (1) it's not wireless and (2) when I tried to run Pandora and Waze at the same time, it became very glitchy/slow. So, I don't use it anymore.
If you're looking short term (2 or 3 years) or don't plan to use the unit like a tablet to run every app from the Google Play store, the price is good IMHO. If you want stability and quality, go with Alpine. There's a reason they've been around forever.