I usually do a bit of both. For example, a blueberry sorbet, I will puree and strain the berries. Probably boil down about a third of this to an intense syrup, then add it back to the "fresh" juice. This you can add to the simple syrup and spin. You can play with this all you like, but the result are some layers of flavour, a mix of intense and fresh.
Also, sorbets love contrast. A hit of acid, not so much that you taste it, will perk up everything else.