I have bar-end shifters on my Bike Friday and find them very easy to use even though I had never used them before I got the bike. I have different types of shifters on all three of my bikes, and it only takes a few miles of a ride to get back in the swing of using any of them if I haven't ridden that bike for awhile.

If I've been riding my Bike Friday, I find myself reaching for the "phantom" bar ends on my Trek (which has Shimano brifters), but I quickly correct myself!

The only problem I've ever had with them, as another poster mentioned, is very occasionally hitting my leg on one of them in certain maneuvers, since I am petite and have a short effective top tube.

Enjoy your new bike!