I tried very very hard to avoid dinos in my new setup with dry rock (after my old setup was decimated by them). I seeded the tank with all sorts of live sand from other established systems. I dosed N+P to keep nutrients from hitting 0. I ran UV sterilizers. In the end it didn't matter and I ended up with some pretty bad dino outbreaks. Fortunately the things I was doing, such as running UV and keeping the nutrients high, ended up allowing me to deal with the outbreaks.
My opinion is the best way to avoid dinos is to have a mature tank with a relatively high fish load (which keeps nutrient levels up). The best way to get a mature tank with a high load of fish is to take your time in the beginning, add fish slowly but surely, and deal with the algae issues as they come. Then give it time. If you do get dinos it isn't going to bother your fish, so if you take it slow with corals then you won't have much to lose. Then eventually as your tank matures the dinos will go away and you'll be ready to go with harder to keep corals.
People treat dinos as if they are a death sentence. They are not. I'm quite confident I could put a rock full of blooming dinos into my tank right now and nothing bad would happen. The same tank that 1.5 years ago was full of them.
If I were starting a new tank I'd still use dry rock, because for me the extra time you need to wait for tank maturity is worth the tradeoff of ensuring you don't have any troubling hitchhikers. However depending on the size of your tank and what you are going for in your reef, I could certainly see it the other way too.
