I'm taking ON protein. Called Hydrobuilder - chocolate flavour. Bit on the expensive side but I've always taken ON products.
As I've mentioned in an earlier post, strong stimulants give you the bad "coming off" effect. Long term useage means your body adapts to it then you need to increase the dosage but at the same time you start to depend on it to the point where you hit a threshold. When I use my Pre, it doesn't have any DMAA so you don't feel jacked up then just crash. Nevetheless, still require on and off periods.
Also the whole post workout insulin spike thing is true and does have good benefits but for your average joe blow then it doesn't matter. You still can yield some decent results. Someone like me who is type 1 Diab, can use any amout of insulin for it's anabolic effect providing that I ingest enough fast acting carbs when your body is most depleted. Insulin helps feed your muscle being a very powerful hormone but at the same time can make you fat.