Grab the usual métro 1.MOV (a great benchmark for fluidity, as always!) and insert it into a blank timeline. Play. Notice the playback is smooth.
Set the project settings from the clip properties, which means 1280x720 with a square PAR.
Result: playback is now extremely choppy, to the point of being unwatchable/unreliable for editing.
This also happens if you save the project and reload it afterwards.
This issue does not occur with 0.94.