There have been issues here from time to time. If you think StrongFirst isn't aware of them, use the Contact link here and let them know. I have trouble sometimes, but overall, I'd say it's pretty rare. When I do have trouble, I usually try again, and if it's still a problem, I wait a few minutes and try yet again. And then if it's still a problem, I let someone know about it.
Just my opinion.
-S-