They were less of a problem before the turn-rate change because stabs didn't reach sweet-spot as fast, nor kept it as long. I know I preferred curved stabs over instant stabs. 
This, so much. Honestly the changed sweet spots are my biggest gripe with post-turn rate game. Stabs made sense and were predictable pre turn-rate. I get that stabs needed to be easier to hit as we went from 14 default turn rate to 7 with the first patch, but now 1h is back to like 10-12 and many weapons are at 8-9 ish, so perhaps the old sweetspots are even doable with the turn rate nerf.
My favoured thing would be to go to old sweetspots and give every weapon like a 25% turn rate increase. I just want the consistent old stabs back, where you can chamber purely based on timing because regardless of how you wiggle it, you won't do a way too early or a way too late hit.
I don't know why you have to aim up now rather than to the side
Simple, because only horizontal turn-rate got nerfed in the patch, vertical turning is completely untouched, which means that the old principle of missing your target and dragging back into him to get closer to the sweetspot at close reach still works as long as you use vertical turning.
