to me, mystery ranch makes a great pack IF their frame fits you well. the yoke is of course adjustable, but there is a fairly small window in the adjustment that fits well.... when i get the torso the right fit, the frame no longer fits me well... the popup actually fits me better than their guidelight mt.... i have not bought a SG and probably won't ever based on their frame height, but it's very rare to hear anything negative about them.
if i lived in/hunted in more open country, i would at least try a SG, but i want no part of a 26" frame over here on the coast getting hung up on everything non stop.... if the MR doesn't carry weight really well for you, it's worth trying a SG.... packs are a big purchase, you are ahead of the game if you buy the right pack, then you don't need to worry about wondering if there is a better pack out there for you.
my suggestion is get a SG this time, if you like your MR better, sell the SG (they have great resale) and buy a bigger bag for your MR.
i have bought and tried a bunch of packs over the years, and there is a big difference in comfort and capability between them.... my list of favorite packs may not be the same as the next guy, but in your position, it's worth trying something different, because if it's a better fit, that's a "game changer" (i hate that term, haha)
