I' recently bought a few tweener racquets and noticed how differently they played allthought their head size was almost the same. One is a 2010 Head Micro-Gel Challenge OS and it, like many other of it's kind, is very light and a bit head heavy, making it a little hard to get a decent smap on my service motion. So I decided to add weight to the the butt-cap to bring down the balance point and also add some weight to get more punch on my shots, using a combination of lead tape and good-old American nickles! since a nickle weight 5 grams, I used glue and lead tape to add 17 grams and then used some chrome strips, used for trim on cars that I had laying around to add 3 grams to the yoke. The extra 20 grams brings the weight up to alittle over 10.5 oz and now uit seems about 2 points head LIGHT which makes serving much easier. I use a wheelchair when I play, so I need all the extra power I can get, but I don't want to swing a heavy piece of lumber around the court, like I did, 25 yeras or so ago. The Wilson K-Factor Bold that I bought next was also very light at 9.8 oz, but was 2 points head light and tghat was the first racquet that I have ever owned that I was able to get the snap at the top pf my serve, like no othwer, but lacked a little "punch" in the groundies, so I enhanced the head-lightness by adding the same 17 brams on the butt-cap and 3 up a little higher on the head this time. I used the chrome strips at the 9 to10:00 and 3-2:00 positioned on the sides, that also provided protection from the scrapes I get, covering low shots. Now I get the most snap AND power on my servs, than ever before, almost as good as when I was able to use my legs! I also have a Fischer M-Pro 98 No.1 that feels to be around 4 pointys head light, without strings, so it may not need another penny-er nickle to get all the snap I need and at 330 grams, 10.8 oz, might pack enough of a punch, too, on it's own. I'm waiting on delivery of a new Babolat Y-105 and it's said to have an even balance, so I anticipate it needing at LEAST $.25 to make it feel the way I want. Lead tape is much more expensive, by weight than a nickle is, save the buck$ for new string jobs, as you will be breaking them more often, with your new found power!