I'm using Alpaca for more than 1y. I guess I was an early adopter. At the beginning was a disaster, so many issues from Alpaca and Polygon.io (they still use Polygon.io as source of data). For many times in the last year I tried alternatives, like:
- TD Ameritrade: the web socket sucks, too many limitations and issues. The support team took +3weeks to respond me
- IB: I hate to run a gateway application in 2020. They have Web API but in 1y there are no updates, same shit with bugs and poor documentation
So I keep using Alpaca and I have to say that in the last 3 months was pretty stable. At least they fix the issues quickly and they are always on the chat.