I'm with dr325, it has to weigh at least 12.5 oz for me to play with or else I need to change my strokes. If it's stiff, the light stuff will probably bother my arm. So I look for the heavier stuff, preferably already modified but I'll modify it if I need to.
So why are you giving this a try if you're reasonably happy with your Pro Stocks? Just playing around? I find that it is so much work to find something that I like that once I like it, I try to stick with it for a while.
4 x IG Prestige MP, 70 cm, 376 grams, 386 SW, ALU Power @54, Prince Syn Gut 16 @58