VST 3 is better than VST 2 because the # 2 is one number higher than # 3 so it has to be better.
Simply put the only reason I choose VST 3 over VST 2 is for its side chaining capability's.
That and it seems the direction we are going in. Cakewalk supports it, its newer technology.
I don't want to be that guy who has all VST 2 plug ins when they drop a bomb saying VST 2 will not be supported anymore. This could be in 3 years, maybe 5 years. who knows. We all thought DXI would last forever didn't we ? well it has stood the test of time but it will be gone as well soon enough. Its probably just a coincidence but I find VST 3 has been more stable than my VST 2 plug ins are. I still use VST 2 plug ins but not if I don't have to.