That's a standard compact Mac layout, so muscle memory will work fine for Mac users. Maybe Fn is elsewhere for the PC one, but I detect a tiny bias in the website.

Whilst I always used a full keyboard with a PC, for the reasons you give, the Mac has practically all of those things mapped to cursors + meta keys so your hands don't need to move from the normal typing position. I now see the extended bit of the full keyboard as dead space that makes me reach further to get to mouse/trackpad. But as you say, everyone is different.