Well I left Start just over one month ago. Signed up with them in November 2017 with just internet service and then added the StartTV when it came out in November 2018.
Never really had any problems with the internet, but when there was an issue it was mostly due to Rogers. Start’s customer service was always helpful.
As for StartTV, well had a lot of the same issues others were experiencing and reporting on DSLR about the STB. The channel freezing (especially CTV London), video and audio out of sync, horrible PVR playback controls, etc. I always hated Android streaming boxes in all their various forms.
Funny thing was that I only subscribed to Start TV Light package, but I was getting the Sportsnet and TSN channels as part of the package!
So when they asked me why I was leaving, I said it was due to StartTV. I have gone back to Rogers as it the only viable service where I am and already a Rogers mobile client. Bell only offers DSL even though they did put in Fiber Optic around my neighbourhood area. It just does not come to our townhouse!