Ok, I exagerated QUITE a bit on how far unlevel they were. I was going off of memory. Got home tonight, and it looks like the back of the tracks are about 3" higher than the front. I have attached a pic.
Here are some other observations I made:
It looks like they mounted the spring bar 2-3" lower than the previous one was mounted, which means they also mounted the tracks about this much lower. They re-used the existing mounting brackets where the back of the horizontal tracks attach, and as you can see in the picture, they mounted the tracks as far down as they would go on the mounting brackets, rather than putting longer brackets on or extending the ones that are there.
It seems to me that this is what they should do - leave the mounting brackets where they are, but raise the front side up - meaning raise the spring bar and all brackets up a few inches to level the horizontal tracks out. However - a problem with this is that I can tell that they cut the bottoms of the veritical tracks so that they'd fit where they are, and raising them up a few inches would mean they're that far off the floor, and in other words, they would need to replace the veritcal tracks. Given that the tracks come from the manufacturer, they'd likely need to order new ones and they might not be so happy about that.
But I think they were just being lazy when they installed these - they actually arrived at about 4:55pm to install this door, and threw it up in a little over an hour.
Maybe theres no issue performance wise with the tracks being un-level, but astethtically speaking, I would rather have them level, as this is a room we're planning to make look nice and probably installing laminate flooring, etc. It also means that in the front the tracks are probably 3" lower than they could be, giving us less space there.