Rating: 2 / 5
Purchased a 2009 version of the Marmot Essence in October 2009 on some deep sale at REI (roughly half-price if I recall). It has a white (with gray pattern) inner lining (unfortunately, I cannot recall whether it is Precip Plus or Membrain). Specs for the current (2011) Essence model suggest it's 6oz, but my gear list says 9. I do not have a scale at the moment to determine whether that's a mistake or a decrease in weight since the 2009 model.
The jacket has served me reasonably well for two years, but showed flaws in extended rain and durability.
I have a size medium which fits fairly close and surprisingly has enough arm length for most applications. I'm somewhere an inch or two over 6 feet (haven't actually measured since HS, I think) and 160-something lbs.
The jacket is nice and simple: waterproof zippers, one small chest pocket that will hold a camera+ (or the jacket itself). Shockcord hem adjustment usually works but sometimes the toggle slips. The cuffs are just elastic. I thought I wouldn't like this, but they've worked pretty well even though I can't cinch them down to my wrists or expand them to insert glove cuffs. The hood brim works well. The adjustments for the hood opening (cord around opening with toggle at either side of chin) work fine, but I find the tab on the rear for adjusting hood volume to be almost useless. If I crank down the volume, nodding my head forward and down can undo the velcro. Not a big deal though. I would call the hood almost helmet-compatible. I've used it twice with a climbing helmet, but it pulls the jacket up off the shoulders a bit and the closure is tight around the nose/mouth.
There are no pit zips, but there are hooded vents under the arm pits. I have never had trouble with them leaking and I do believe they actually provide some modest venting in some cases. However, breathability is OK at best. Under heavy rain it suffers and even seems to wet-through (after the DWR has worn off).
The lining shows wear in the waist and along the back (not surprising given my tendency to carry a pack!). As of about 6 months ago, I noticed small tears in the lining on the shoulders. These have since grown to be a couple inches in length and the lining has started to delaminate further. They leak plenty. Additionally, I feel drops falling onto my head inside the hood even in light rain, if prolonged and my whole forehead eventually becomes wet even with no exertion (i.e. not sweat or condensation). I suspect some seam taping is loosening here, but I have not pinpointed it.
The actual shell fabric has survived just fine. No rips or tears, though it has not seen much stress beyond pack wear. (No heavy bushwhacking, etc.)
In a 2-day heavy rainstorm on the Tahoe Rim Trail in late October 2010, the a fleece that I wore under the jacket became quite wet. Though I have no proof, I believe that in addition to condensation poor breathability (likely reduced further when the jacket wetted out), there was actual transmission of water through from the outside, especially near pressure points.
My use has been backpacking and commuting by foot and bike in Seattle.
If you will use the jacket only lightly and/or can get it heavily discounted, I recommend it for its simplicity and light weight. However, it will not stand up well to extended/heavy rain or long-term frequent use.