The "problem" is that I using a MLD eVent Soul Bivy, which I love and has been holding up great since 2008, but it is 13 oz.
Add a 15 oz MLD Solo Mid, I am pushing into the weight of a Tarptent Notch.
If I had your bivy, I would come out great with that combo, but I am not willing to give up my current bivy....too much invested into it in terms of money and it is just great.
It does have a silnylon 2.0 floor, which is pretty waterproof, but might wet out after long periods of time on really damp ground.
Learning lots here about how considering "one" change can effect the whole balance of gear that I am using.
My setup now if great for the Sierras, but if I wanted to head to the Pacific North West, I have to consider having more protection from rain.
I like the flexibility of just using a bivy to sleep out under the stars and in small spots that might not allow a tent/mid/tarp and then using the Mid with the bivy when things get bad, but I do have to question if a tarptent would be better.
I do have a Contrail, which I have not used in years, since going to the tarp and bivy.....
Just mental games to think about between trips.
Again, appreciate the advice from everyone.
Ultimately, in very rainy situtations, sounds like a mid, bivy, and groundsheet might be in order....but better to carry some extra weight vs. being miserably wet.