A few comments:
Most reviewers on the REI site liked it, but nearly all had problems with condensation inside the bivy. If you're using it in cold weather, you should consider a synthetic bag instead of down if, indeed, there is a signficant condensation problem.
Bring your bag and sleeping pad to the store and see if they, and you, will fit inside. Depending on your pad, you might have to have it outside the bivy. If you don't roll around a lot, shouldn't be a problem. If you do, then you'll probably roll off your pad if it's not in the bivy with you.
You might want to glue a small loop on the mesh, so you can lift the mesh off your face for sleeping. I notice a lot of the reviewers mentioned the mesh on the face thing, and they didn't like it (most people wouldn't, I'd think. A bit of glue, webbing and shock cord will take care of that.
It's a tad heavy.
Overall, looks fine for someone who just wants to try bivying without spending a lot of money. Just be prepared for its limitations, and realize not all bivies have those limitations.
Let us know what you think of it if you buy it!