Hey guys, just thought I'd share for anyone who isn't doing this, but for the best smooth slow motion in Vegas, I almost always slow down to 50% ( which makes a good slow motion ), but I also like to add a motion blur envelope on the slomo segments. which *really* smooths it out.
This is especially useful when having to slow down further than half speed. It's not always perfect, and you have to make sure that use an appropriate amount of motion blur. I usually do 1-3 frames depending on how much I slow it down, and you should really adjust do to taste, but that's a general guide.
Anyway, just in case you aren't already. Motion blur with your slow motion makes a very nice looking result.
Your mileage may vary.
Dave