I just used this for the first time for a 12 day hike on the Long Trail. I'm 5'10, 170 lbs and I found it just a tad bit tight for me.
I'm a side, curled up sleeper and if you push your unclothed self into the sides of the bivy (i.e. before the air is cool enough to crawl into your bag), those pesky skeeters can get you right through the netting.
So, if you are smaller, a back sleeper or someone who does not curl up (or you always get into/under your bag or you wear clothes to sleep). This will work great for you.
I used this with a patrol shelter (which I love by the way) and it fits perfectly. The craftsmanship is excellent.
$50 plus shipping.