I went with a ST Pro (NIB). It's my first pin. I absolutely love it. I added a shaker, Aurich's alt. translite, added the Enterprise & Klingon Ship, some Mezel mods (spring cover, vengeance explosion, and diffuser), some protective plastics from Pinbits and Cliffy, Comet's DMD glare guard, external volume control, super bands, etc. and still saved a significant amount of money verse what a premium would've cost. I now have more money to put towards my next pin too.
I'd say, if you work hard for your money, get the Pro, you won't regret it. If money is falling out of your pockets, go for a Premium. You really can't go wrong either way!