RE: Do you notice a less clear, sort of grainy picture ...
I have only checked Imax 3 and Stretch Max so far, and the lighting is softer than in the other series, but other than that and Cathe's tan I am getting a very clear picture.
The picture is definitely not as crisp as previous DVDS (not including the workouts that started on video and were transfered, like PS and MIS). It's also rather shady around the edges (because of the set?). On Kick Max, I noticed something like a light flash or a streak on the image everytime they jumped after the "front-rear-center" jacks. Almost like light was being reflected off someone's watch.
If you are having your picture appear grainy, you might see if you have the progressive scan on your DVD player. Most DVD players, cheap or not, have option for progessive scan or interlaced scanning. Mine looks much better on progressive than interlaced.