My Game: 4.5, 2hbh, full western grip. Play with Youtek Radical Pro, stock. First Impressions of the IG Radical Pro: The two main difference in spec that stood out to me were the balance, IG listed at 320 mm vs. 325 mm of the non-IG, and weight- IG 310 grams vs 315 grams for non-IG. I measured balance with overgrip/dampener and IG came in at 5 pts headlight, while my non-IG’s average 4 pts headlight. While both have 16x19 string patterns, the IG is noticeably tighter. The IG’s bottom cross is almost even with the non-IG’s second from the bottom cross- and same with the top cross as well. The result is that the IG is more like a 16x20 pattern IMO. The grip is synthetic leather, which I prefer to the leather of the non-IG. Feel: The IG feels more muted on impact, with the non-IG feeling crisper. As for flex, the IG is rated as stiffer but I could not tell the difference. Perhaps the Innegra technology is the reason for the more muted feel? Groundstrokes: The non-IG has more power, producing consistently more depth, and hits a heavier ball than the IG. The IG swings noticeably lighter, which helped when I was on the run but a little less stable on mishits. The IG's sweet spot felt a little lower than the non-IG. Topspin was about the same between the two. Volleys: The IG shines here- perfect blend of maneuverability, stability, and pop. This was my favorite shot with the IG. Return: Slight edge to the IG. Lighter but still enough power and stability to get the return back deep. Serve: The IG was similar to the non-IG on spin serves. I served with more mph on the non-IG, and just a more heavy ball in general. Conclusion: These racquets are not that different- I switched between them during a set and was dialed in within a few points. However, I am sticking with the non-IG and a big reason is the serve. I felt that the IG did not have enough mass for me to serve big and get enough free points. However, both models are great racquets and the IG is a must-demo for those that liked the balance of the non-IG but felt it was too heavy.