Some other things to love:
-more force behind each movement, thrust, etc., just for their sheer size/weight
-being hugged from behind by one and feeling totally surrounded by butchness :-)
-"borrowing" a big butch's shirt around the house - so comfy!
-watching one fawn over something fluffy/furry. Butches making a fuss over animals in general is endearing, but there's something special about watching a particularly large butch reduced to a puddle in front of a furbaby
-the sight of a big butch on the back of a motorcycle

-ever had a butch with a nice, round rump model a really cute pair of boxer briefs for you?
-bear hugs
-big butch, big boots. 'Nuff said. :-)
-they look awesome nekkid (I mean, everyone does, but I think they look extra awesome)
Basically, there's a lot to love. I'm more aware of big butches in just plain physical terms because they simply occupy more physical real estate. I love to explore those hillsides (with permission, of course)...
My most recent ex (not on BFP) was about a size 20-ish (which I don't find all that large) and 6 ft 1. I can remember seeing her for the first time and thinking "my god, she's an Amazon." It's a miracle I was able to keep my hands off her as long as I did. Would I still have been attracted to her if she had been smaller or shorter? Sure, but that lethal combination of both length and girth is dynamite for this femme.
I think confidence is key if you can unlearn and unpack some of the negative messaging society imprints on you about larger bodies. I know it's hard and it's a constant battle but I have to say, seeing a larger butch with confidence is a
huge turn on. It's important to remember (for anyone) that the more time you spend fidgeting with and putting down your own body, that's time you could be giving someone else to appreciate it in all its glory. :-)
From one big-butch-loving femme, please feel free to show off a bit more.