Been using a few days and I'm in love. It's pretty easy to set up, I wish it was similar to the stream deck where you could "see" your OBS sources rather than having to hand type them. Lazy, I know.
Haven't had any real issues with it so far. The limit of a free "action" is 3 which is usually enough to activate/wait/deactivate a source or filter. That being said, $3 a month is extremely affordable as an upgrade if you're planning to do some complicated stuff.