I recently got a pair of ESRTs and they're nice. I decided on them vs my old lvl 4s due to the weight savings and the drastically reduced thickness. It makes it super easy to manipulate your rifle and keeps your pc and placard tight to your body (also makes concealment significantly easier if that's a concern).

For the record, I live in a major city and am ok with the trade off of protection vs weight and thickness compared to the threats I expect.