The magic mouse is far from perfect but I do like the touch scrolling and gestures etc and it does work very well with the OS. They're also really slim for putting in bags and so on. I haven't really used anything else for a while, I always find that although they're invariably (ok always) more comfortable than the MM I always always miss the gestures.
Make sure you try one of those Apple mouses before you buy one - I loved the look of them until I got my hands on one and it was just too small and flat for me to use comfortably.
I actually have the trackpad as well (not the new one) but if I could only have one it'd be the mouse. I use the trackpad on the sofa etc.
If I could get one for a fiver, I still wouldn't. They're rubbish!
I use the mx master. It works great on my Mac, custom buttons are a nice feature. If like me your hands are anyway big, it'll feel great. It's much better in the hand compared to a Magic Mouse. I do also from time to time use the original track pad which is great for gestures.
Been looking for a replacement to my temperamental M560 (which I loved) and went for a Razer Orochi.
Had it 5 minutes and its going back. Cheap, nasty, horrible feeling thing with sharp edged and it dropped off Bluetooth twice.
Ordered an MX Anywhere 2 instead.
MX Anywhere 2 arrived and is great. Highly recommended.