Hey there!
I also have a mini2, I updated yesterday and honestly haven't had any problems. I've used slide over, picture-over-picture features (not split screen 'cuz it's only available for iPad Air 2 and mini4), Siri, multitastking, almost everything and haven't had any issues so far TBH. Maybe I've noticed a tad of lagging when using spotlight by sliding down from the screen, but don't notice it when using spotlight by sliding to the right.
Hope this helps!