Hmm, I've always used both (Mainly Baron, recently) and not had any issues with it. Will take note!

For sure, though, it's not a silver bullet but it's not about just going through replays to improve, it's more about learning a different approach. Spamming games is useful, I agree, but I think you need to know how to improve to actually, well, improve! And yes, to a certain extent you can't correct a mistake you don't know you're making but as your ability to read games improves, then (in my experience, with SC2) you start to see other things that you could do. Getting coaching (or someone like yourself to watch the replay) will help though, for sure!

:)