Weather was nice today and had a chance to hit with each racquet below for about 30 minutes.
Steam 99S - Very easy to swing and like others have mentioned, it definitely is noticeable the increase in topspin. Racquet came strung with 4G mains and multi cross and racuet felt very comfortable and solid. Usually polys give me sore shoulder but this felt really comfortable. I think with gut mains and poly cross, this racquet will play even better. It's very easy to generate racquet speed and swinging the racquet felt effortless due to the nice balance of the racquet.
Speed Graphene MP - This is a much improved racquet over the previous IG Speed MP. It felt very light and whippy and you could really generate a lot of racquet speed. I definitely what Head has done to their entire line of racquets using the Graphene tech. It improved the IG by offering a more solid feel and I didn't feel the harshness so they did a good job. I had difficulty keeping the ball in play with balls sailing long which I attribute some to the multi string that came with the racquet.
Speed Graphene Pro - This is a very solid racquet and those that like their racquets polarized, might want to take a look at this racquet. When you swing the racquet, you can definitely feel the weight in the head moving through the contact zone. It hits a solid ball and like others mentioned, this 18x20 particular racquet does offer more pop compared to other 18x20 string patterned racquets.
2013 Blade 98 16x19 - The racquet is just solid. Think of this as a bigger sized version of the BLX Pro Staff with a tad more stiffness and increased sweet spot and ample amount of power. I have an easier time keeping the ball in the court with the Blade 98 than the other two Speed Graphenes. Wilson did a good job to the blade and hope they don't tinker with it too much.