Btw, I've heard that hitting down with the driver is safer, but I've also read that you can lose about 30 yards of distance.
I don't quite agree with that notion. If you hit up on the driver you have to worry about wind since you're launching higher and if you're long enough, many fairways tend to bottleneck. But you can still hit it pretty straight and hit up on the driver. The LPGA tour average is +3* with the driver and I'm assuming that there are some LPGA golfers that are extremely accurate with the driver.
You can gain, easily, 30 yards by hitting up on the driver. I believe JB Holmes and Tiger have the same swing speed, but the difference in Holmes being longer is he hits about 3* up with the driver while Tiger hits about 3* down.
But, you gotta find what you're comfortable and most consistent with, IMO. I think if golfers force themselves into hitting down or up and they can't quite do it, it can lead to some trouble.