After several months of poor Internet connection, I now have like triple the speed I did before on a good day.
New provider? No, actually, they just came over and fixed the problem. (Yes, on Sunday.) All it took was a rare break from my executive dysfunction issues to call my ISP. Guy came over, fixed the problem, and also upgraded my router.
Anyway, I'm gonna try streaming at 1080p tonight, see how that goes. YouTube VODs will still (arguably) be better quality, since they're saved losslessly locally and compressed down from that, thus skipping the Twitch side of things. Super Shuffle starts in about three hours (or as soon as possible thereafter).