I use all 3 PPC. I use Adwords, AdCenter and YSM. On my very own personal opinion I rank YSM as the lowest performing, the slowest and the more intrusive one (even with the adwords quality S###). I will rank AdCenter as # 2. Their interface is awesome result are pretty acceptable and research tools are good to. As YSM AdCenter is kind of slow. And for number one my best performer and easy of use is Adwords. And for speed it may go a bit slower some times but it will defenetely out rank YSF and AdCenter. I will like to know how you guys rank them.