I didn't mean to sound quite as harsh, hence the "in my opinion". I have had issues with their shafts personally, there have been many threads here aswell with shafts warping, delaminating and ferrules breaking in half and the few cue makers that I'm friends with have shared their stories about most production cues and from what has stuck to my mind OB hasn't been gathering much praise from them either. That said there are a few other companies & makers that have their issues aswell. Predator for example is also notorious with their ferrules on older shafts along with a few other hickups but their all around build & finish quality has been way better than that of OB from the cues and shafts that I have owned so they still remain a viable option for a cue in my books.
OB does have some really nice folk working for them as you stated. I think it is nice to see a president of a massive company personally comment on facebook posts etc. but that alone doensn't make the brands product better quality or worth recommending to others to me :frown: I'm glad you've had a better experience with their products though :smile:
Play well!
On topic:
I have owned and played extensively with all Mezz shafts currently in production so I'll try to chime in a bit here of what I think of the shafts you asked about;
The single biggest difference with WX700, HP2 and ExPro is the core.
WX700 doesn't have a core and therefore it has a rather natural hit with shaft flex that you'd expect from a maple shaft. A good shaft with not much tech stuffed in it.
HP2 has a very stiff carbon core so it has a very crisp hit to it. This is a personal thing if you like it or not. The sound of hit has a higher pitch than a WX700 for example from what I've experienced.
ExPro is something between the two mentioned earlier. It has a carbon core but it is clearly not as rigid and stiff of a core as the HP2. The hit is softer feeling & sounding than a HP2, more towards tge kind if hit that the WX700 has. ExPro is also more flexible than the HP2 with the stock taper and even more so if you like to alter the taper by taking it back some like I do.
Deflection between the three is within reason with all 3 so that alone shouldn't be the deciding factor in my opinion. You'll quickly get used to it regardless of which one you go with if you are used to LD shafts already

Go with the one you think you would like the most feelwise. That is hard to do without having a chance to hit a few balls with them but from what I understand that is not possible for you to do so hopefully these replies give you an idea of what the shafts are like.