So I started a new character a few days ago and now want to download dawngaurd. I'm currently level 9 and haven't fought the 1st dragon yet. Should I download DG and proceed with this character or download and start over? Any pros and cons to either? Or does it not matter? Thanks

Based on what I've read in the forum, the DLC has caused game breaking bugs to the original game for various reasons, not the least of which is that vampire attacks can kill important NPCs. I have only 1 play through on the Xbox & finished the main quest before starting Dawnguard so newly-introduced glitches were not much of a problem for me.