The Taylor K2006 is very similar the PS234 (most or all of the reagents in the PS234 are Taylor made) and functionally I think they're identical. The primary difference is that the amount of the different reagents included in Ben's kits are optimized for the way most people really do pool water testing. You'll get more of the reagents you use most often (e.g. pH and chlorine testing) and a whole lot more CYA reagent. In other words, the PS234 is a far better deal and you won't run out of key reagents as often.

The other big reason to buy a PS234 is that Ben (aka PoolDoc) makes it and buying his kit is a small repayment for the great forum he provides here.