chuckyup,
I believe that most vets suggest staying with one angle for awhile. However, I am concerned that this allows some tissues to heal (strengthen) while other tissues are stretched. This creates stronger limiting factors. The fact that different angles can take different loads supports the idea that different tissues are being stressed at different angles. I also think that 1 or 2 sets at a particular angle stresses the tissues to an adequate level for growth. Consequently I vary the angle between each set in a workout. I do 5 - 6 sets total. The sequence I use varies but an example is SD, OTS, SD, OTS, SO, SO. Another is SD, SO, OTS, SD, SO, OTS. I do this while laying on a bed watching TV or reading.
sheLovesIt