My current stem is at 7 degree rise and I am looking at replacing it but the one I want is a 10 degree rise.
Is this something that I will notice when I ride?
Would I need to make a headset spacer adjustment for it?

Thanks Rob

This handy online tool allows you to compare various stem lengths, angles and spacers:

Stem Comparison Tool | yojimg.net

That's clever.
Obviously as I thought this is pretty minor a change

What's the length of each stem?

Current is 120, I figured to do the same

Positive or negative rise on the current stem? Do you like where it is now, i.e. are you comfortable?
Getting the new stem is purely for looks?

All good questions.

The bike was fitted a few years ago and it seems to still fit fine. Of course how do you know how good things are or aren't until you tweak again.

The change is mostly for looks and perhaps safety.
I have a Bontrager Race and it is a 2 bolt design and was maybe looking towards 4 bolt.
I'm not so worried about looks (i'm lying) but may change my shifters on this bike from 9-10 soon so I would thing this could be a good time to change this also.

until you tweks

Positive or negative rise on the stem now? (+7 or -7)

+7

So a 120mm 10 degree stem will be 3mm closer and 6mm higher. That's not a huge change, especially if you aren't crazy picky about fit.

That's what I figured. The Stem chart does make it much clearer than I could envision.