This is a bit of a small fix you won't get the start of the round but i'm loading up a lot faster and I join maybe 5 seconds after the round started.
Get advanced system care pro: http://www.iobit.com/advancedsystemcareper.php
Do a scan with it and use the "turbo boost" option and configure to your pc's gaming power plan.
Download the razer game booster: http://www.razerzone.com/gamebooster
This will shutdown unneeded background processes allowing more CPU power to go to the game and give you a small FPS and loading time increase.
When you start the game press Ctrl+Alt+Del and open up taskmanager, when it's open go to the processes tab and look for t6mp.exe, once you've found that right click on it and click on select priority and then click on High.
Finally if you're on a laptop the 13.4 beta drivers also help a bit with the slow loading times.
This helps me but I don't know if it will work for anyone else but it's worth trying.