I've been using Crunchyroll every now and then for quite some time and never not had problems (for free with ads, not paying, don't even have an account).
At its best times, it was broken in a way, I benefited from: The ads tried to load, but after a short while of black screen, the anime continued.
At its worst times, the same spot would play over and over in a neverending loop, forcing me to reload the whole vid – meaning watching all commercial breaks again.
This went on for quite a while, it worked as intented rarely.
These days they cracked up the commercials quite a bit – 3 breaks, each often up to 2 min long (what is quite much for a 20 min episode if you ask me). But the real bad part is, that they often throw the videos off synch. During the ad subs would continue in the background, so when the video comes back, it would be way behind the subs. No way of fixing other than reloading the whole vid, sitting through all ads again – risking for it to happen again nevertheless.
Other times the subs would also just disappear, mostly when skipping a bit. Again, no other way to bring them back than to reload.
I understand that they want to politely urge you to pay this way, but given how broken it seems to me overall, no way in hell I'll start doing so.