I love the Zip trainer so much, I ordered a 2nd set just so I would have the medicine ball and core ball for my DD, who started to work out with me during the summer break!
Pretty much everything has been said already about the pro points for the Zip trainer, so I have nothing further to add, other than that I love the short time format and intensity I get from it. As much as I also like the FE workouts, sometimes those are a little bit more 'frantic' when using weights than the Zip workouts.
PS: I'm in both FB groups and you can see I'm more often than not checking in with the Zip workouts! :P (When I not forget to check in, that is! lol)