Vail is not just more spread out, it is much bigger than Breckenridge. There are many more stores, shops, restaurants, hotels, etc. However, if I am going to spend a couple of days somewhere, I personally prefer Breckenridge. There is enough to do and see in Breckenridge for a couple of days and it is all much more accessible. But be careful of the altitude, as Breckenridge is about 2000 feet higher than Vail and Vail is already several thousand feet higher than Denver. Drink lots of water and minimize your alcohol.