i am 6'4, 190pounds, have shot gx680 and RZs handheld, rollei 6000 with 180, no problem.....the H1/2 with the 55-110 is in a completely different league.....it is just too heavy....had a discussion with someone on this forum about this, the outcome was that the lens should be used on a tripod...to me the best thing (and really only reason) to have a mid range zoom is to shoot people, fast and handheld....not sure how strong you are, but with this lens it is a challenge...i can't do it....
i am generally not a big fan of zooms, never liked the 24-70 on the canon, which everybody loooves, for me it is soft and too big and heavy....the hasselblad is a very good lens, crisp with great contrast, i would say the first zoom lens i would use without any hesitation for the most critical work, BUT the main advantage of a zoom for me is the ease of use and this one just does not have it for me if i have to be glued to a tripod....
do yourself a favor, go somewhere and pick it up, hold it up and try and focus manually in the store and the salesperson....i can tell you right now, it will be very hard...now imagine doing that running after someone....for 10 minutes straight...or even shooting in a backroom, or outside in the sun....
i have the 55-110 zoom for my mamiya 645...a very good performer, the fixed lenses are all better, but it is the first zoom i like to use, because it gives me the option to really use a zoom the way it is supposed to be used, quick adjusting to the shooting situation, constantly changing the framing,....
i also use a lot of ringflash for fill, so my distance has to stay consistent, the zoom is perfect for that...by the way; the haselblad would not fit through my hensel ringlight...i have the octabox mounted on it and maybe i could have fit the lens through the front (now that i think about it) but i probably owuld not have been able to turn the zoom ring, which defeats the purpose....
to make a long story short....please check it out for yourself....
ps: i am thinking of making that my signature for the forum here....why would i order a lens for 3?4?5000?$ without even having seen it? because the salesperson said it was a great lens? because everybody has it?