I am not sure how much those weight ratings matter or how much I would believe them. If you are breaking trail in deep powder, neither will be inadequate. If you are on a trail, even just the 3rd snowshoer back in line, you will do fine on either. I have several pairs of snowshoes, including 25" MSRs and various 30" models. It does make a difference breaking trail, and I opt for my largest pair when I am just tooling around in the woods at home. But if I am heading to the mountains and am going to be on a trail, I would always grab the MSRs first. If I get to section that is impassible on the MSRs, and this happens, I have to turn around. But those sections would be impassible on the 30" shoes too. Since you are mountain climbing in Cal, and may carry the shoes, and are likely to be on trail, I would get the 25" MSRs and see how that goes.
I should note that I am 5'10" and about 190 too. The sections that get me as impassible are really deep snow on really steep sections, when I am off trail or can't find the trail. At some point, you can't realistically move forward and make meaningful progress. I don't think the size of the shoe matters then.