Gym Styles came out before the 4D's. She uses many of the classics but she uses the band also. I don't think she uses the band in any other previous series.
I like them but I like her style of lifting - it's more endurance than Slow Heavy but you can still go heavy - I'm going by memory here -I think you do three sets of each exercise for maybe 10reps? I could be wrong and I'm too lazy to go downstairs and look (at least I'm honest);-)
Oh, there are lots and lots of pushups in this series.
I don't know if someone would see better results than other series because results are so individual. When I do splits - mostly Cathes - I see strength gains. It would just depend if you like splits, traditional weight work - no functional fitness stuff - no balance challenge stuff and you like finishing your work with "bonus burns" with the bands.
If you don't like taking a long time to learn a DVD, this is a good one- nothing unfamiliar.