In general I tend to be pretty easy on my equipment in terms of wear/durability, but recognize one can't really control the shooter's shot power/impact from pucks. That said I'm going to guess that durability isn't the #1 concern. It looks like a 24" Vapor 2X Pro is $40 USD more than a 24" EF4 (and assuming 24" CCM is the same paddle size as 24" Bauer Vapor), so between the CCM and the Bauer price is probably a factor, but not #1.
To be honest I'm not really skilled enough to know what kind of flex I like. I would say that I'm not a strong stickhandler and don't shoot the puck well (literally kind of a weakling and avoid handling the puck when possible), but I have been practicing off-ice this summer with both my composite and my foam core to try to improve so I can add passing/shooting to my game. Subjectively my composite seems to be a tad stiffer than the foam core, but I don't seem to notice much of a difference in shot power between the two. I think that unless the Vapor might offer some advantage for someone with my shortcomings I'll try the EF4, based on familiarity with the blade pattern.
Thanks, everyone, for your insights.