I just spent 2 weeks in a Tigoat large basic bivy on the Tahoe Rim Trail, and it worked well for me.
I have the old head net, which worked well on the few mosquito evenings we had, but is difficult to get full protection.
Because I am 6'3", the bivy is just barely big enough for me, and using the DWR hood pulls enough tension through the bivy to compress the loft on my JacksRBetter No Sniveller, so the new headnet design probably wouldn't work for me.
I can vouch for the 1.1 oz nylon DWR... When I woke up one morning on the trip after a good nights sleep, I found others who had slept out in tents, and rain jackets hung as make-shift tent flies.
Apparently it had rained for 20 minutes that night, directly on the bivy (my head was protected by a tree), and both me and my down quilt were dry.
That's really all you can ask from a DWR fabric, I suppose.
That being said, given the funding, I would definitely upgrade to a MLD bivy. You get what you pay for and them Soul bivy's look awful nice.