There's nothing wrong with the racket. No resonance issue or whatsoever. The main reason being is this particular model are more suitable/designed for pro-level players (not necessary pro-circuit players but players with very sound wrist/arm power and hitting technique). With its extra stiffness rating, any powerful shots combined with flawed skills would have certain amount of reverse energy (unused torque) transferred back to the player and in your case, shoulder pain. Bear in mind that any racket with head heavy + extra stiff rating has a very minimal tolerance. That is the signal the body relates to you that it couldn't handle this weapon. In a reverse scenario, a racket with such specification would definitely generates shots that are much more powerful and threatening compared to its lesser counterparts. Its all about handling or getting strained.
You seem very absolutist in your opinions. I actually played very well and capably with the MX80 for a full year before I started having issues, and the only variable that changed was I got older. Your comments as to my 'flawed shots' and 'inability to handle this weapon' are incorrect because you have nothing to base this on. Nobody has said that there is anything inherently 'wrong' with the MX80, so you can rest assured in your purchase without the need to belittle people whose abilities your are not familiar with. I'm an Industrial designer and product testing and evaluating is something I've been doing every day for almost 20 years, so I like to think I'm pretty well qualified in judging how things handle and feel. Just because I call something 'metallic and mechanical' doesnt mean people won't like that feeling. If you don't agree, pick up other similar stiffness rackets like the BS10, SW35, Ti550S and tell us how you think they feel compared to the MX80.
I can sense big ego here. My post did not refer to any anyone in particular nor I mentioned that your skills are flawed. It seems to me my statements were very general. I was quoting on your post simply because the point of discussion you were talking about... MX80 and your shoulder pain period. Now you'd make it clear that you play all right with good skills and the cause of the pain wasn't because of MX80 I am happy for you. As for all the rackets you mentioned, I owned one of them and tried the other two many times and I can tell you they weren't as stiff as the MX80. At least one notch lesser in difference and could be handled quite comfortably. The MX80 is a beast! At least to amateur player like me.
I've been using 3U MX80 for the past year and decided to give a try on 3U MX 70. It's slightly lighter than my MX80, and as expected slightly flexier. I use MX 70 when the shuttle is slower then usual, when I like to play a lot of lob strike, defensive play, or when my fitness level is not 90-100%. In my peak condition and feel like to play fast and attacking play MX 80 is my weapon. It's a nice MX series line up that suit for my style of play and condition.
Cosmetic changes effective 1st Jan 2013 according to the Victor website: 因我公司球拍生产工艺升级，2013年1月1日起尖峰系列球拍MX-80/MX-70拍框五、七点处水标略有调整。 变更如下图所示：
