A "lag" or a "drop out?" I would say that big movies would be problematic when streamed over slower networks, but N speeds should work fine, but that's just a supposition because I haven't tried anything about that stuff. But a "lag" is when you issue a command, like "pause" and it takes a noticeable amount of time for the pause to happen, while a "drop out" is when playback ceases on its own. Knowing which you're experiencing will help determine what's going on.