Coming from a BLX Pro Tour (and Pro Staff 6.1si before that) I expected this racquet to be just as arm friendly as the BLX. I was disappointed to encounter tennis elbow for the first time in my life (been playing for 35 years). The Steam 99 LS was much more arm friendly and in truth I found it to be more fun. Yes the Steam 99 LS is a lot lighter and has less plow thru than the 99 but the 99 LS was an amazing surprise and really fun. If you think the ultra light racquets are not in your wheelhouse I would challenge you to try the 99 LS.
I have been demoing several racquets, such as the AeroPro, Juice, and ProStaff. I felt the Wilson Steam 99 was the best so far. I have been looking to replace my current racquet, Wilson Pro Open BLX, due to wear and tear. The Wilson Steam offered a lot more plough through and I found that the 16x18 pattern added more spin without the loss of control. The additional weight of the Steam 99 compared to my current racquet also added more pop on my first serve. It also seemed that my volleys were more controlled. This will definitely be my next racquet.