In my experience, the non-leveling lap sealant isn't strong enough for the areas around your gutters (especially the "downspouts"). Under the gutters.. maybe.
I did my whole camper with Dicor everything.. spent a couple of weekends re-doing all the sealant around everything (walls, windows, doors, trim, etc).
It all cracked out the first trip.
The only Dicor product I'll use now is the self-levelling lap sealant on the roof around vents, pipes, etc.
In my opinion, Pro-Flex (specifically the clear) is better and much stronger.