RKS
Pros
* Great production values
* Shot outdoors with fantastic views of LA
* Good music
* Hunky male leads with great form
* A good variety in length of workouts (10-30 mins) and mix of bodyweight and kettlebell exercises.
* The short length of the workouts makes them easy to mix-and-match with other workouts.
* Great packaging
* Great customer service
Cons
* Inadequate instruction for KB newbies, and relative newbies
* Female backgrounders have terrible form
* Following the provided rotation may present problems (too many back-to-back shoulder-intensive exercises)
SKOGG
Pros
* Stellar instruction on a separate DVD
* Programmable DVDs with 4 levels of intensity
* Michael Skogg has impeccable form and no-nonsense personality
* Background exercisers have great form
* Good production values
Cons
* Shot indoors in a dark gym-like setting (I know this bothers some people)
* Only six "foundational" exercises - doesn't have the variety of RKS
* Kettlbell exercises only (this could be either a pro or a con, depending on how you look at it)
Verdict
If you are confident with kettlebells and crave variety, I'd go with RKS.
If you like no-nonsense workouts, and feel you would benefit from extra instruction, I'd go with Skogg.
My experience
I bought RKS first, but didn't feel confident with snatches and high pulls, so bought Skogg. I did it for a while, but became bored with only six exercises. I'm looking forward to doing an RKS/Kettlebell Kickboxing rotation next year.