I guess I'll be the first to say I enjoy using Maxpedition packs for this, at least, the day hike part:
[...]day hikes and even over night trips[...]
I've used the Falcon-II, Pygmy Falcon, and Condor-II for hiking. My personal favorite is the Falcon-II. In fact, I actually bought another after selling my first and trying a few other packs in between (camelbaks, osprey.... Still want to try others, like gregory, mountainsmith, kelty, etc.)
I use my Falcon-II for day-hiking, and it's packed such that I would be better equipped to survive a night (or a few nights) out unexpectedly. Would I want to use it as a dedicated overnight pack? I could probably squeeze in a minimal set-up that'll still make for a decently comfortable camp in temperate weather... but realistically, no, not large enough for the things I'd like to take. And I have to agree: I wouldn't want to haul 30-40lbs or more over 10 or more miles of terrain with decent elevation changes. I'd take an Osprey or the like for that. Functioning waist/hip-belt + frame + harness and straps adjustability = comfort with long treks under load.
BUT, for the niche it fills for me, it's great. I haven't gotten into backpacking yet, but even when I do, I'm reasonably sure I'll still day hike more than I backpack. The pack is perfect for me in a use-often, day hike role. I could care less about the military styling, but it's very durable, well-constructed, and well organized (subjective value). I like those qualities. I take care of my gear and don't do many crazy things, but it's nice to know I can be rough with the pack if needed, and that it'll last me a LONG time. And, I'm an "everything in its place" kinda guy, so the organized nature of Maxpedition packs appeals to me.
As for day hiking, I know I can carry 20-25lbs in it (dropping down to 12 with water and food consumption) over 11-12 miles of hilly terrain and not feel uncomfortable at the end of it - even without a frame and functioning waist-belt. And I'm confident I can do it over and over again for at least a few years without noticeable wear on the pack. Furthermore, I can go off trail, squeeze through tight spots, fall and scrape along in a slide, or throw the pack about without worrying about tearing it up or otherwise damaging it. I have been EDC-ing a Pygmy Faclon in commuting to and from work every week day for the last year, and the only wear I've noticed on it is that the padding on my right shoulder strap is no longer springy (I often just shoulder carry with that strap). That's it. I don't claim to have tons of experience with other packs (that'd be expensive

), but few of the other packs I've used or handled have inspired that kind of confidence for me. Also, I tend to think that the sort of things I'd do while day hiking would wear more on a pack than the sort of things I'd do while carrying a full backpacking load. Even if they're the same sort, my dayhiking pack would get a lot more of it.
If I were rich or inclined to stop buying knives and save up for it

, I'd look to get a Kifaru. Based on what I've read here and elsewhere, it seems they've succeeded in putting together stuff that's BOTH durable and comfortable. In the meantime, Maxpedition's price is more doable for me. And it's not my only pack. I currently use a Golite Rush when it's a short hike or I want to go light and fast, and I plan to pick up another Osprey down the line for overnighter/short backpacking trips.:thumbup:
This is a pic of my original Falcon-II in use. I just bought another one. I've sinced learned that attaching stuff to the MOLLE isn't for me. It affects my balance too much, especially if you mount pouches on the front of the pack vs. the sides. I can take pics later of my current loadout if you want an idea of what a Falcon-II can hold.:thumbup: