Just plain ordinary house brand painter's caulk will do. It's water soluble when fresh and I usually work with a washrag in one hand to correct drips/bumps while I go along.
Side note:
( As a matter of fact, so long as the label says it's paintable you could use any latex caulk at all...this could be a good way to get rid of any you bought for trailer-sealing use before we all came down with both feet about using it instead of butyl putty!

)
Do take care to build it up in coats/layers, as directed on labels- if you apply it too thickly all at once it doesn't cure well and may produce cracking.
Donna's stippling idea is a good one- I'd do that as a finish coat once the seams are level with the surrounding Ensolite. On that subject, if I was trying for a totally seamless look, I'd probably use a razor blade to bevel the Ensolite edges some. Idea being to provide a level plane, at least in the most visible areas. But I'm compulsive in the painting-prep department!
Francesca