Used to be you could pick a new game or one from your game list, and download. Zip, zip. These days you pick a new game or one from your list, then find something to do. Read, watch a movie, etc. BF really needs to boof up their downloader.

I can only speak from my own experience, but I think there are a number of reasons for slow downloads.
I have a cable modem. Sometimes downloads seem to take forever and sometimes download time is quick. Factors include traffic on my own Internet provider, file size of the game (games continue to get "bigger"), and traffic at BFG (as they continue to add members) which increases during sales, as well as the day of the week and time of day. BFG can only address part of these factors. And extra bandwidth costs extra. I prefer that BFG keep prices low rather than increase bandwidth and raise prices. JMO I always find something to do while waiting for a download, just in case.

I'm sorry it's so slow for you. Sparkle is right, though, that the reasons can be various. For myself, I don't have what is considered a high-speed connection, and I'm finding that the download times have remained pretty much the same.