Dropped it to 37 minutes on my third run.

That would be cool if others could help directly but unfortunately, this isnt a server, and putting a single player map into a server messes up the nether world. BUT what you can do is download the map go to the last place i built and make a whole bunch of jumps a little after it ( Like 200 blocks out a direction), then can build towards that in your file and then TA DA! You helped out :)

and yeah you cant split a minecraft map in 2 parts, lol, but dont worry, future updates will be MUCH MUCH smaller, since i loaded a HUGE chunk of the playing area on the x4map, so the next updates, and following 30+ updates will still be 81mb as long as nothing big is done. BTW if its taking you so long, make sure you arnt downloading anything (utorrent, gaming online, youtube vids etc..) or ya it will take longer, but i got a bad connection myself and i downloaded it to test and it only takes me 30 seconds

its only 81mb man, lol yeah i wouldn't recommend it to anyone who still uses dialup xD, takes an average person like 2 min to download, a watching a youtube video is like half of that.