I use a belt kit similar to this one instead of a vest:
Professional photography equipment - camera bags, camera cases - from Think Tank Photo
I purchased my pouches individually (different than the set linked), and just add and subtract as needed. More customizable, better support and protection for the gear.
In general, the vests are a good idea (spreads out the weight) but I don't like how most of them are designed. Also, you can't reconfigure the pockets, and I find that I'd be stuck with empty ones when there's nothing I have that fits in them. I played with the idea of getting something like
MOLLE to use for equipment (I mean, fishing vests work...) but the cost compared to something designed for photography (i.e. ThinkTank's Modulus) made the endeavor not worth the cost.