I have beeen using Wilson k Factor six one for about 8 month. Great Racket. Superior control, great serves. I was making some great shots. Then about 2 month ago my arms started to hurt, while I was using this wilson.
Rabbit,
Why you are not using C10 anymore? I thought you said you liked it. Why did you switch?
Did you ever change the strings during this time frame? If so, it might be them. If not, it might be dead strings! Anyways, just one more thing to think about -- strings are cheaper to buy than a brand new racket, that's all.
I moved from the C10 to the AG100 because I wanted something a little lighter and easier to use in the heat. The AG100 has proven itself to be an excellent alternative. It is very arm friendly and much fun to play with. It, IMO, serves better than the C10 and is very friendly around the net.
From my experience, I found both the 5g and C10 sluggish on the serves. The Ki5 has more pop on the serve than the other two. (All in stock form).
now the OP is getting info from those arm friendly racquet users (good company to be in ).
so how well does the OP serve? btw - this poster doesn't have serving issues with those racquets listed in earlier post.