I've done both. Sometimes, I'll write up a few notes beforehand and have them with me (a couple times, I've had a whole page of typed notes!). I won't always refer to them, but it can help having them there in case I draw a blank. Or if there's an important point I want to make but not forget.

So I say write something up, bring it along, then see how you feel in the moment, whether you need the notes or not. I've also brought something (typed--my handwriting is awful!) that I handed my T to read (a few times with Dr. T and once with ex-MC).

I hope it goes well!