Most of what is sold in the stores as "vanilla bean" ice cream seems rather bland to me. I much prefer French vanilla. In fact, the preference is strong enough that I won't buy vanilla bean anymore -- even if it's simply to serve a la mode with pie or something else.
I love the custard-like flavor of French vanilla.
Now I have found a reason why people who use an ice-cream maker at home should prefer French vanilla. At SimplyRecipes, Elise writes:
French vanilla is a bit more complicated than regular vanilla or most of the ice cream recipes that come with the machine, as you need to prepare a custard mix by cooking the eggs and cream first.
But unlike many homemade ice creams which can be a little on the ice-y side, because of the added richness of the egg yolks, French vanilla stays creamier -- at least for the first day or two in the freezer.