Earlier on, I used 6.5mm three-fingers, probably the same type you're using, down to 4C(40F) water/-5C(20F) air. I didn't have any particular issues either. On the first dive, that is. But putting on a pair of wet, cold, maybe frozen wetgloves for the second dive? That sucked royally. And while I can't say that I lose as much dexterity as
@stuartv seems to lose, I really appreciate having five normal fingers on each hand instead of two normal ones and one big one. It's easier to manipulate my camera's controls, and I can signal "3" or "4" unambiguously.
So I'll rather take the risk of a dryglove leak. I wear wool liners under my drygloves, and air travel between my suit and my gloves is ensured by sticking a short piece of bungee cord under the wrist seal. In case of a major leak, I can take off the glove, pull out the bungee cord to avoid flooding my arm, put on the glove again and continue the dive with one wet glove, still insulating decently because of the wool liner.