That's great Glenn. After practiceing with the "rhythm method" for a while you can count on two things:

1) you will be able to fly the rollers in your sleep
2) you'll get thick callouses on your thumbs

The rhythm method as you're finding is good in that your thumbs start to realize on their own the 90 degree "out of phase" action which they need to perform to keep the roller going. For mode II, the sticks "chase each other" in circular motions 90 degrees out of phase.

With practice, I think you'll find this WILL translate into real life, HOWEVER, you may tend to get "locked" into one speed or direction with real planes, and if you hit a wind gust or other "Real life" situation the rhythim will need to change, so you'll have to delay or quicken the timing of some motions to keep pace with what you're seeing (rather than just let the constant rhythm keep things going)

I like to fly the sim to Music, and I find some songs really lend themselves to roller practice.

Also, I'd like to add another item which may help you when transitioning to outside. If you have an unobstructed flying area that gets smooth air on a breezy day, WIND is excellent for roller practice! It keeps the plane in one spot and you can really see what the plane needs to do cause it stays in front of you if you stand downwind.

Check out this video as it illustrates what I mean. Skip to the end to see the rollers there are some in windy conditions (check out the white/orange plane as it does rollers into a wind which comes from the left as the plane stays relatively stationary in space).

http://www.tufflight.com/tufyak2.wmv

Have fun!
Joe