The main difference I see in Isidore from the other systems is a difference in stages. All of the rapidly strengthening systems you mentioned were young and tight. To look at Isidore is to look at a middle age man. He is somewhat big and flabby. A youngster will grow stronger a whole lot faster then a flabby middle age guy. Not exactly the same when it comes to storms; but it is going to take a lot longer time for a storm like Izzy to pull together and tighten everything around the central core then a newer growing system. Yes, the energy and pressure is there. I just think that the flow and inertia of the all the flows will make it a longer road harder road for our middle age storm to tighten up the flab. Hence, no more then cat 1 minimal Cat 2 if this forecast path pans out. If Izzy idles and stalls, then stronger is definately possible if not probable, IMHO.