Commenting sure. But until some instance agnostic subscription feed comes out it looks like there is no reddit alternative to a reliable subscription feed right now.
Having to juggle multiple accounts to keep track of subscription feeds instead of one unified feed is a pretty big con. Not so much on the commenting end since that I do understand the reasons for.
I don't mean so much in activity. Just the subscription to communities part.
Like knowing I could subscribe to like gamedeals and pcgaming and knowing that I can rely on my feed to contain posts from those communities as opposed one of them defeding from each so now having to subscribe to separate instances of pcgaming and gamedeals to see activity from those communities in my subscription feed. So now having two subscription feeds as opposed to one unified one to keep track of.