DART for publishers is a great solution for large publishers because quite frankly, most big advertisers use their solutions. That trend is changing as more open source solutions are hitting the marketplace but they still offer a very robust solution. I used DART at a previous company for 3 years and outside of the price and occassional trafficking tool blimps, had no major problems. I would not recommend this for smaller publishers as their set up fees and CPM-based pricing model gets expensive when you don't have high volume impressions or a high effective CPM for your inventory.