Yeah, don't fret, they're just able to compress it further.
There are some things to remember, though. Unreleased drivers are often unreleased for a reason. They might be perfect for some people, but not so good for others. If you're a bit of a noob, messing with your system might not be worthwhile, especially if it seems to be running perfectly. As the saying goes, "if it ain't broke, don't fix it". They won't make anything explode, but it could be annoying.
If you are interested in experimenting with different drivers, or even if you upgrade to the latest official drivers, as many of us do from time to time, you should be aware that it's best to completely remove the old driver. When you install a new driver, a few files will be left from the old driver and these can cause a conflict on your system. To avoid this, you can use a simple freeware program like Driver Cleaner.
http://www.softpedia.com/get/Security/Secure-cleaning/Driver-Cleaner.shtml
You can use this to clean up after all kinds of drivers, not just for video cards.