Spraying is easier, that's for sure. I am new at it though, so most of my rolled restorations look smoother than my recent sprayed ones. I'll dial it in as I go. Spraying is also a little more nerve wracking than rolling.
Look in to Floetrol... add about 20% to your paint and it smooths out everything...even if you use a brush with it it will smooth out the brush marks...

