Unlimited Google Drive, honestly. It’s nice being able to keep an offsite backup (but not the only one, of course) of my NAS in the cloud.
I assume they’ll get rid of it at some point and then I’ll move, but it’s surely handy (OneDrive is completely terrible UX wise and has a 5TB hard limit).
I actually prefer the flat aesthetic of MS services, not sure what UX you're referring to. Yes the storage limit sucks but other than that Outlook and One Drive are not any laggier than Google's products to me and they have all the basic things I need (plus some ads, admittedly). Needless to say MS office is superior to Google docs.