I wonder how close the Alpha is to a mcdermott I-2? They sound like very similar designs. I am sure the mezz is higher quality but I'd be curious about the hit and feel. I wish the WD700 was just a tad thicker, as I would prefer a shaft closer to 13mm than 12.5.
I don't own a i2 shaft, so I can't comment, but i do own a i3 shaft and all the Mezz shafts, so I can try to compare for you.
you should aso read my: "The big Mezz shaft" thread in the cue and shaft review section.
Even though both companies uses a carbon fibre rod core, the feel quite different.
The i3 shaft is very stiff for it's 11.75mm tip diameter. The way McDermott have constructed the ferrule system for the i shafts gives a hit that to me lacks feeling, it's a bit dead. The taper is really nice and the quality of the shaft seems to be very good.
The Hybrid Alpha is the largest tip diameter shaft Mezz offers. The taper is more conical, resulting in a stiff hit, the ferrule is quite a bit longer than the i shafts and made of a softer material (Nylon) the carbon fibre core must be constructed in a different way, you can feel it is there, but it's not as pronunced as in the i shafts.
To me personally I find the combination of conical taper, carbon fibre core and the big tip diameter to be too stiff and it's just too thick a shaft, especially on shots where I need to use a long bridge.
The Hybrid Pro 2 shaft has a 12.5mm tip diameter and a much longer taper, to me that shaft feels much nicer.
But since you are asking for a stiff big diameter shaft, the Hybrid Alpha might just be what you are looking for?
I also mentioned the new Exceed EX shaft, wich on the face, looks very similar to the Hybrid Pro 2.
I have not tested that shaft yet, but I have noticed that the ferrule is a bit shorter than the HP2 shaft and the rumour is that it has a different, slightly softer feeling carbon core.
One thing I have noticed with all carbon cored shafts is that they feel very harsh if you are using anything harder than a Medium hard tip. I like those shafts best with the softest playing tip I can find. The ones I have liked are: Kamui brown SS, G2 S, Zan Plus S, Zan Premium S and Moori S.
Of those the Zan Premium Soft, followed by the Zan Plus Soft and G2 soft has felt the best.