I'm a level 60 Breton mage and I've purposely caught vampirism a couple times to try to work with it, I was at low levels so it was pretty hard.
Can anyone share any strategies? The destruction spell looks pretty cool and I use duel casting sparks a lot. I'm playing at adept with low health and a ton of magica, if that helps.
1) I've found that playing a Dunmer as a Vampire tends to work best. Their natural 50% resistance to Fire helps a ton as a Vampire.
2) The Skill bonuses to Sneak, Destruction, Illusion, One-Handed, etc. are very sweet, and the while these bonuses don't increase as you gain levels, it is still a higher number than you would have had otherwise.
3) Unless you are planning to run around almost entirely at night, keep yourself well fed. This typically means stopping by a town at least as often as when you hit Vampirism Stage 2. The townsfolk/citizens will not attack you on site until Stage 4, but they will react less than... friendly if you let it get to Stage 3 (you are very visibly an Undead Predator by this stage...). As long as you keep yourself well fed, combat even in the day is still a chore and needs to be planned carefully (you lose all of your Magica, Health, and Stamina regen until the sun sets or you go inside), then there shouldn't be any problem.
Generally, once I hit Stage 2 or 3, I will simply head for the nearest hold capital and do all of the non-adventuring things that I need to take care of, and then I'll wait around till about 1 am, pick a lock, and much on the local flavor.
Following this short guide has greatly eased being a Vampire for me, and being a Vampire does help to give you an edge over the people and creatures that you meet while adventuring. Plus the Vampires Sight Power has pretty much ensured that I never miss a treasure chest or bag of loot due to a dark corner.