Wsup GT? Well if you're looking for that insulin spike i'd go w/ the MRP. Even though Maltodextrin is complex carb (some are some are not) it will shoot up insulin levels much like your regular Dextrose and Protein shake. Problem w/ the Maltodextrin is some of it is actually simple sugars not bonded together, and if you get a cheap Maltodextrin you're going to end up w/ a bunch of it nonbonded. What makes it complex is that it's suppossed to be bonded together, but not all maltodextrins are created equal. From what i read this is what i understood. So i think Maltodextrin is a bit of a rip off b/c you really don't know the quality of it.
Well about your AM cardio, if you want to shoot up insulin the MRP is a great idea as well as your regular dextrose/whey shake. If you have Oatmeal you will have a much longer sustained release of carbs, but combined w/ whey, the whey will be in and out of your system in less than 2 hours. IMO it depends on how much time you have on your hands, and when can your next meal be. If you have time to square in another meal before work i'd go for the shake then in an hour or two eat the oatmeal and something solid that's protein like eggs.
One question though that i'm not too sure about... Is the whey/dextrose or MRP really all that useful after morning cardio? I know after you lift you need it, but do you really need it w/ cardio too? I personally find it a bit harder to lose weight when i gulp down the shake after cardio, but that's what a lot of lifters have recommended to me.