I use the ACT ablative paint. Having it on there gives me the confidence I need when I leave her in the water. Now that I have it ont there I leave it in the water most of the time, but I will trailer it to Hatteras a couple of times a year.
That is where the problem comes in. I have a trailer with bunks (not rollers). Though easier to maintain, it does a number on the paint when I put it on/off of the trailer and I have to touch it up each time. Therefore, I try to avoid trailering as much as possible.
Be sure the bottom paint you choose has the ability to haul it in and out. (Most ablative paint does)
From what I understand, the Barrier coat is necessary if you aren't going to sand the bottom of the boat prior to application.
I had a professional do the paint the first time (they used a primer coat) and this year I put it on myself. Not too tough a job, but it was messy. Make sure to use (at least) two coats when you apply.
Anyway, I love having the boat in the water while maintaining the ability to trailer it/take it out. I have seen what not having a bottom paint on your boat will do if you keep her in for more than a week or two in the summer... I use the boat a lot more and getting underway is a whole lot easier/faster than drydocking or trailering.
On the other hand there are some drawbacks too. You will have to maintain the paint and you will lose a couple of knots off of your top end while increasing your fuel consumption due to incread drag.
In my opinion: If you are going to keep it in the water more than a two weeks at a time, do it. Otherwise, do not. If you do paint it, keep her in the water.