I used this bivy in Alaska last year (late summer - early fall). If you are in for lightweight, this is a good option.

Comparing to the conventional bivy, this is pretty good. But it's definitely not something you will be comfortable it.

First of all, I woke up every morning wet. The condensation on the inner wall is terrible. You can feel water dripping down.

Second issue, it's pratically pretty hard to climb into this small tent/bivy. Imagine that you have to go leg in first. It will be especially hard if it's raining and your tent is surrounded by mud. You do not want to touch the mud when you work your way into the tent, so it will be a challenging task to get into the tent feet first without your body touching the ground.

if you think you can live with these two problems, then go for it by all mean. it's really light and pack small.

5 nights without rain in Nankoweap, Grand Canyon this tent was perfect, not yet sure how I will enjoy with rain, but I will bet it's better than a bivy.
Set up was easy, used a different stuff sack to save weight but still brought the small pump, (barely over 2 pounds this way), could have done without it. The pump allows you to increase the air pressure in the bladder, but in calm weather is not needed. Works best when staked out at foot and head, but one night on a rock slab used a rock on the head point and my hiking pole through the feet loops with a rock on top and it held just fine, faster set-up and take-down. Plenty of room inside, able to watch the stars through the screen.
Only a half pound more than my bivy, and packs nearly as small, tough call what to take on the next trip.

These guys are great from the lifetime guarantee, free shipping, return anytime, friendly approach. The NEMO go go is one of the best constructed solo tents I've seen. I do worry that the narrow tunnel design will contact the sleeping bag and wick moisture to the bag.