Putter Loft

Im playing 4* loft on my SC Newport, just interested to hear what loft others are using and do you have a definitive reason for the loft chosen at purchase.

I use 4* to help get the ball on top of the grass and start a consistent forward roll, however if I am playing a course which has recently been aerated or if my putting line is in a stripe of mowed green in which the lay of the grass is away from me I will apply ~2* of forward press.

Thanks for the replies.

SC standard loft used to be 4 degrees, but has changed it to 3.5 degrees. If one plays on your quality, smooth greens, the change makes sense to me. However, I doubt many of us get to play on greens that smooth. So, I'd like to know what loft is recommended for us mere mortals.