Hi Adam. First of all, thanks for always having such a positive presence in the ABDL community, despite not being ABDL yourself. Its great to have someone who takes in the input of the ABDL community, and not solely people facing incontinence issues. Supremes have been my favorite daytime diaper for awhile now. They are sturdy, fit snug, absorb a lot, and are very affordably priced. It's thus very exciting to have Northshore producing a new high capacity diaper. As for the MegaMax:
Overall I think this is a very solid diaper. The absorbency is great. The plastic is soft but strong. I really like the front plus rear waistband. The tapes hold well and don't come off easily. They don't wick as well as the Supremes, but I think that is common for high capacity diapers and I wouldn't want to be wearing a diaper that swells so much for active wear anyways (that would be more when I would wear the Supremes, or maybe a Supreme with a L size booster).
For sizing, I can't give a definite response as I usually wear a medium and found the mediums a bit too large for me (I'll order a small sample to see which fits better before I order my next case). Still, even being a bit large around the waste for me in this size, the fit on these is very satisfactorily snug at the legs. Prior to the MegaMax, my main high capacity diaper has been the ABU Simple (the Peakaboo being too pricey for me). I found the of the center of the MegaMax around my inner thighs to be snugger fitting than the Simple and thus less likely for me to feel like I might leak (when not wearing a pad).
As for improvements, as others have stated, the Northshore branding is too prominent. Even if the ink was lightened on future prints, ideally I'd like to see the print only on the front wings and then only further on the sides of the front wings. This is how the ABU simple is printed. The result is that the branding is visible when putting on the diaper and changing, but covered up when the diaper is worn. While this might have less of a billboard effect while one is wearing the diaper, I think it still prominently advertises the diaper well enough. It would also make the diaper a lot better for photo shoots for ABDL who are into that, which in turn would increase free promotion of the brand.
For tapes, in one comment you said you were thinking of reducing the stickiness to make them less "Gorilla Glue" like. If you're going to do this, be careful. One of the biggest problems with early new diaper batches it weak tapes. Its very common to see a new premium ABDL diaper come out and be great overall, only to have terrible tapes. This is not the case with the MegaMax, so please be cautious as you proceed here out of worry that the tapes could become not sticky enough.
Lastly, my only other comment is that I wish the leg guards were a bit taller. Measuring the height of the leg guards on large size ABU Peeakboo I got from from a friend (the size closest comparable to a medium MegaMax), I found the leg guard height of both diapers to be 1.75". Comparing the height to an ABU simple, however, I found them to be about 25% shorter, with the Simple leg guard height being 2.2". For most wear, I don't think this makes a difference, but when wearing with a booster pad, the shorter guard can lead to leaking much faster, and leaking before capacity of the diaper has been reached. Even with the higher MegaMax capacity, I still found a Simple + pad having a longer wear time before leaking compared to a MegaMax + pad. Ideally, I'd thus like to see taller leg guards.
That's it, though. Overall I think this is a great diaper. I think it's still a close call for me between this and the Simple, due to the leg guard and pad issue as I normally wear with a pad. Either way, these are a great diaper at a great price. As a Chicago local I'm proud to support Northshore and your products.