I work out in my living room where my TV and DVD player are. So I use DVDs.
My computer (a desktop type) is upstairs in a small spare bedroom, so a download would do me no good.
Also, with a large TV I can see what's going on, I wouldn't be happy watching the workout on a small lap top computer screen.
But, if I were going to take a laptop to the gym, to use their equipment instead of working out at home, then a download would be perfect.
I'm guessing that there are ways to play a download on a TV, but I'm not computer savvy enough (nor do I have the equipment) to do that
I think it all boils down to where you are going to do your workouts and what equipment you own.
Welcome !! I'm new to Cathe's workouts also (June) and I'm loving every minute of it.
The workouts are fantastic !!