I've had some recent experience with this. I started riding my old Trek hybrid last spring and summer and decided I wanted a road bike. I wasn't comfortable transitioning to drop handlebars and clipless pedals all at once, and I really thought I liked sitting upright, so I had flat handlebars put on the Specialized Sequoia I bought last fall.

After riding quite a lot this spring, and especially after doing a weeklong ride in June, I wanted the drop handlebars put back on (thinking it might help with the feeling of hot nails being hammered between my shoulders after riding 89 miles upright).

My LBS suggested I try a really long stem for a couple of rides to see if I was really comfortable stretching out, like I'd be when I would ride in the hoods. I did that, and then I decided to go for it. So two weeks ago, I had my bike put back they way it was when I bought it, and I love it!

I wouldn't worry for a minute about transitioning from a hybrid to a road bike. It will just take a few rides to get used to it. I don't know if you use clipless pedals or not, but for me that was the bigger change. If I had it to do over, I would have changed out the pedals to non-clipless until I got used to the feel of a road bike, then put the clipless back on. I would have saved a lot of money.

Now I go back and forth between the hybrid for commuting and the road bike for weekend rides, and I don't have any trouble at all. Have fun shopping for a new bike!