100gb wasn't enough for me. A family subscription to office 365 offers each user 1tb of storage and the price is reasonable compared to the competition, especially if you're already ok with paying for Microsoft office.

How does it compare to dropbox? I'm happy to pay a bit more

I'd rather avoid Google if I could so I don't get further locked-in with them, but its a minor issue, and if they do end up being the best whilst keeping out my way then that sounds like a good deal to me