Keyframes are shitty wheels imo, slow as f*ck and won't slide at all. If you're actually looking for a wheel for crusty park + cruising with which you can do some tricks on, get 56mm Dragons.
Keyframes are objectively, far from a shitty wheel. They are great cruiser wheels and do not chunk apart easily from riding on some crust/rough ground. Are they the best? No, not at all.
I got Keyframes rn and been running them since 2017. Your mileage may vary is the takeaway with a wheel like a Keyframe, ATF, Dragon, etc. They work well: standard workhorse cruiser/rough terrain wheel.
They keep speed well, especially if you take care of the bearings. Could feel somewhat slow sometimes when you're bearings aren't spinning as well, though. Ride is smooth, grind on coping fine, can even grind ledges, and the slide is minimal. You'd have to really push to get them to slide. There's some give, but not enough. If you wanna slide at all, these may not be the ones to pick up (if you haven't bought yet)
For overall cruising and some flat tricks, they will work just fine