Got a chance to hit with the IG Rad Pro tonight. My first impressions were along the lines of "not worth it" but that was with some jive-prince-poly strung in the high 50's. Took me about an hour to work through what was left of the string life then I strung it more to my liking 50/53 Bomber/OGSM and it plays much much better. The frame hits pretty nicely and has a great feel when you properly center the ball. Having said that, I noticed that the "center" or sweet spot is a bit lower than what I'm used to. An inch or two makes a significant difference in feel and sound signature. Hitting a bit higher, the frame almost sounds ping-y and harsh while finding that sweet spot has a great feel and much more feedback on the ball. You know you've hit a good shot when you find that spot. I did play pretty well and consistently with it though and have to say that I think I like the slightly tighter string pattern that it provides.
Where I think the frame could use a little work is that it feels rather light. Spec wise it's within 6 grams supposedly but I feel like adding a bit more weight to it while keeping the same balance would suit my preference. Design wise, Head really did a beautiful job here although they traded out the traditional black for a dark coffee and gold.
At the advertised price on TW, it's definitely worth the 10 extra bucks simply for the cap grommets and an up-to-date warranty. I like this style so much better because it actually protects the racquet (Although they sometimes can be a fantastic PITA). Grommets cost 6.00 to replace; a frame 170.00. Protect the darn thing and not just on the tip! Having played both frames (YT and IG) with the same string, I think the IG has a bit more zip on it than the YT. I found control levels to be very similar on both frames.
Edit: After hitting with it for a bit more and switching back and forth, I don't quite think it's worth the extra $$$ for the switch especially since my wrist is hurting for some reason after playing with the IG for 2 days