It looks like I'm the first reviewer and I have a feeling I know why.  This is one expensive rain jacket!  Probably the most expensive WP jacket I have ever purchased.  But, it's worth every dime!  I'm a small guy so I purchased the small size in black and I absolutely love it.  It fits perfectly.

Is it lightweight?  This is the lightest jacket I have ever....EVER owned!  It's called Helium for a reason!

The quality is impressive as it should be.  Perfect for the ultralight backpacker and extremely compactable.

I'm impressed with my purchase and would do it again.  I've used it a number of times on the trails in the pouring rain and never got wet!.

UPDATE: I've had this jacket for a while now and I love it.  it is so light!!!  I've carried it all over the place for all sorts of trips and never even noticed that it was there due to it's light weight and compactablity.  I do notice it when it's pouring the rain and I'm thanking god that I have it.  The fit is perfect and allows for an additional layer if need be.

Most recently I did an overnight backpacking trip into the Linville Gorge in Western NC.  Day one, hot (HOT), full sun.  I almost got fried.  Day two.  Praying for clouds and rain.  I forgot the sunblock.  Packed up my tent and bag in the morning and took two steps and the rain started!  Put on the jacket and spent the next 4 hours hiking through some incredible, flooding downpours.  Stayed perfectly dry (chest wise).  I couldn't be happier.  I should say that the jacket breathes very well.