The parallel will be slower. There's twice as much metal for the same amount of power to heat. You're taking the same amount of power that once went through one coil and sharing it across two. So if you parallel at .6, then each strand of wire is actually pulling the power of a 1.2.
It'll be less noticeable with a single parallel than with the standard dual equivalent because you essentially have a dual coil build with both coils smushed together and thus sharing heat, but it'll still ramp up slower because that alone is not enough to make up for the loss in power going to each section.
However, that's assuming the same gauge of wire is used in both instances. The thickness of the wire determines its heating properties. The thinner the wire, the faster it heats up to its max and the less heat it retains. The thicker it is, the hotter it can get and the longer it takes to get there. Since you are going from a single with a thicker wire to a parallel with a thinner wire, the ramp up time may actually be comparable.
The added surface area will give you a flavor and vapor boost, but with that increase in surface area inevitably comes higher juice consumption. I wouldn't consider it too significant in your case. If you doubled up on the 26 at the same resistance, then you'd start seeing a real difference in juice consumption. A single 24g build would probably go through about as much, which at .6, is still going to be on the low side... ...by dripping standards, anyway.
