Pros
Circular Energy is one of the best places I've ever worked. As a young professional, the team atmosphere, the direction and freedom the leadership teams provided was inspiring. They went through a few management teams while I was there, the first (founder) had his head in the clouds, but tried to hire people that could build efficient & effective teams. And when that didn't work, they hired and appointed managers whom all tried new ways to make the company successful. Eventually, those managers, and the founder, came to the realization they were over their heads, and brought in investors to properly capitalize the company, and get it pointed in the right direction. They have recently been extremely successful in hiring (and firing) the right people, and I still know some of the guys that work over there, they were the best of the bunch.
Cons
The company has gone through growing pains, and made some major changes, which has caused some anger with previous employees (see other comments). They've made attempts at hiring hot-shot sales guys, and managers, that have produced absolutely nothing. I've heard they have gotten rid of all the dead weight...and are now lean-and-mean, wish them the best.