I currently play with a Mezz Exceed and I have 3 Mezz shafts (EX Pro - 29", WX700 - 29" and WX900 - 30") all with wavy joints.
WX900 was my shaft player for about 18 month now and I recently received the EX Pro (abount 1 week).
As weight comparison, EX Pro is 3.25 oz, WX700 is 3.75 oz and WX900 is 3.50 oz.
In terms of playing, WX900 is more like the WD700, but with a smaller tip (12mm). It plays wonderful, but it is very unforgiving. It moves the ball a lot (in terms of spinning) and it is the easiest to apply draw with. Nevertheless, it is the most difficult to consistently play with because it requires all your attention/concentration at all time, which may become difficult. Also it has the least deflection from all Mezz shafts and the most feel.
I played only few shots with WX700, so I prefer not to include it yet into my review. It seemed to me as being very close to a Predator 314-2 in terms of deflection, but with a lot more feel than 314-2.
EX Pro feels similar to a Hybrid Alpha to me, with very consistent play. It has a stiff feeling, but not as stiff as a Hybrid Pro II. I do not know if the difference in stiffness is from the shaft technology or it is only due to the soft tip (EX Pro has a ZAN Soft + tip). It has less deflection than WX700, but a bit more than WX900. Although I played only 1 week so far, I like it a lot. It is very forgiving (compared with WX900), very consistent in long shots and, surprisingly, it has a lot of feel (compared with an Hybrid Pro II), more like the WD700. For sure, it will remain my playing shaft for a long time.