I can only comment from my own experience, but if a Pitts is your goal, then don't bother with the Cub - just crack on and get some instruction in a Pitts S2. I did my tailwheel conversion with Alan Cassidy at White Waltham in the Pitts S2, and highly recommend the experience.
For the first couple of hours, you will wonder what the hell you've done, and feel completely out of your depth. Actually, this sensation goes on, intermittently, for hundreds of hours, I understand, long after you've been signed off to fly your own Pitts. But then, that's why you fly a Pitts....pure, unadulterated joy most of the time, and a few seconds of the exact opposite on occasions when you land it. But if you have the opportunity, do it....