I don't have any experience with this jacket, but have been on a similar quest the past few months. And since we have had a lot of rain, there has been ample opportunities to experiment.
I have been re-evaluating my shelter and rain gear. Have decided to move away from the poncho/tarp & bivy combination to a large tarp without a bivy, which requires a W/B shell jacket.
A few months ago I stopped by REI to look for an around town jacket and a shell for BPing. Ryan Jordan had made some nice comments about the Marmot Essence (Brainstrata fabric), but REI did not have them.
I looked at the Shuksan, which is similar to the Kimtah, but both are too heavy for BPing gear IMO. REI had a Marmot Oracle on sale for less than 1/2 the price of the eVent, so I bought it for around town and some testing. I really liked it.
During the last half of 2009 I had been using my DriDucks a lot, and the zipper is contantly problematic. So based on the Oracle experiment, I bought an Essence at around 6oz. I am thrilled with this jacket, and for me it does a good job as a windshirt too. One caveat, I am a desert dweller, so am less likely to overheat than most folks. Bottom line is that I know have a large shelter, rain and wind coverage at 16 oz total.
I think the REI eVent jackets use 3 layers versus some of the lighter brands that use 2 layers.