Halo fans may want to look away now. 343 confirmed recently the dreaded news of the download size of people's digital pre-orders and it's huge.
The MCC was nearly 50GB for four titles with further Matchmaking updates, pushing it up to the grand total of 60GB for your precious hard drive space. Well, Halo 5 is 60GB right off the bat. We can only assume (as it is coming later) that they're not even mentioning Forge in that grand total.
Looks like October and November are going to see lots of external hard drive sales. Good news for you Seagate!