Not sure about your shaft. I have a WD700 with my Mezz cue, and it is a decent shaft. With the standard tip it grabs the cue ball more than most cues. this can be bad or good depending on your style of play and the conditions that you are playing under. I generally use a Universal shaft with my Mezz now, but on occassion I will still use the WD. The WD is a little softer hit (stock) but will put a lot of spin on the ball. Deflection is not bad with the WD, but the Universal is an improvement IMO. The WD 700 does have an insert joint, so make sure it will match your non-Mezz cue well.
I have tried a lot of different cues including the Customs, and my Mezz is the cue I have settled on for the last few years. I have a friend with an old Joss, and they hit pretty close to the same. They are not very popular in the USA yet, but I would recommend Mezz cues withouit hesitation.