My putter for the last four years. Went to the local course and looked over all of the putters but this one really caught my eye. It looked sharp which is NOT what you want out of a putter, unless you're of the mindset ”look good, feel good". It definitely wasn't comfortable in the hand at first because there is a line of plastic around the disc that fits into the crease of your palm, but the beauty of it is that if you use it enough, it goes away! 

It doesn't matter what disc you use within the circle, most people I've talked to say it's about what is most comfortable in the hand. That said, you want something reliable from outside the circle where the putts really matter, and for me it is the Ion.  This biscuit requires a little pop in the right direction and it takes care of the rest. The magic happens from 30 - 80ft out which the glide eats up without asking for seconds, shaving strokes from your round 

The Ion was the first MVP disc I ever bought.  I enjoyed it enough to buy many more.  Looking back though, it's nowhere near my favorite.  It is slightly overstable, but barely.  Honesly, it flies a lot like an Axiom Envy, except doesn't feel as good.  The interior of the rim is rounded, which gives it a weird feel for driving.  It is very solid off the tee, with the ability to hold many lines, but everything it does, the Envy does better.  Buy the Envy.  

The most comfortable putter out there.
Untill the recent additon of the Axiom Soft Envy, this has been and still will be a go-to for my main putting needs. Its an excellent approach disc as well. One thing I've found is that both regular and soft proton arent too different in flex and feel. I have about 6 of these things and I rotate depending on how I feel, but there's really nothing you cant do with this thing.
The glide really helps out with approaches, and can even work as a good driving putter. My main Ion has taken a few hits and is decently seasoned where I can get some turn out of it, and the fade is minimal.

You're missing out if you havent played with this dics.

Love the 175g Eclipse plastic. This is my go to for a longer put. It feels great and flies like an arrow.