Love this disc! I've tried it in electron, neutron (soft and normal), and eclipse. I find that the neutron soft and eclipse fly like a beat in envy, the neutron and electron fly exactly like the numbers, aka extremely straight and pretty far for a putter.

This putter is great especially under certain circumstances. The circumstances being you normally throw a more stable putter and want some range. This is a nice addition to a bag as the understable putter, as its extra turn will give more distance for long puts. Also, doesnt seem to spit out.

I own a half-dozen Cosmic Electron Proxy putters with different levels of firmness (soft, medium, firm), and there is a noticeable increase in stability with each step up in firmness. All three plastics offer exceptionally accurate putting; however, I prefer the soft plastic for putting as it seems to stay straighter for longer distances and clings to the chains a bit better on glancing shots. The firm plastic has proven to be best (and most durable) for drives or longer approaches.

I began using the proxy as my main putting disc when the electron was released. It glides very nicely at low/medium speeds, and flies in a very straight line. It sort of feels like using an envy that fades much less on its way to the basket. 
 

As a thrower, this disc has a bit of turn if I throw it fast, and otherwise flies straight. What I love about it is it's ability to hold the anny on a tee shot. It will hold the line the entire way without flipping too far over. I love this disc!