This will be for back country hikes, ice fishing trips, hunting and outdoor trips. Day trips only but weight and comfort are important. I may be hiking for hours but not overnight.
I have an edc northface pack for daily use.
The pack Needs to hold food, clothes water, perhaps tarp, large knife and saw.
Giving advice is hard since it depends on fit which is personal. Sort of like seeking advice on comfortable boots or underwear.
Some of my personal considerations for backcountry use.
SIZE - I find over stuffed packs uncomfortable. I end up as the "guide" for my family/wife so I end up carrying more extra stuff. I'm also where XL jackets, so my winter pack needs to be able hold an XL primaloft parka. I can get away with 30L for solo summer hikes but for family/group hikes in the summer or winter hikes/ski trips, I carry a 45L pack as I find it much more comfortable.
TORSO LENGTH - I'm 6'3". Short packs give me problems as "hip" belts end up being "mid-ab" belts. With some packs, I can carry them lower on my back, but this depends a lot on the shoulder straps. This is much more of a problem with my 45 L pack due to the extra weigh it carries, and this is one reason I chose a Jandd Zoor Alpinist, since it comes in different sizes based on torso length. And even then, I had to send it back to Jandd to have the shoulder straps moved up another 2". 30L packs almost always come in just one size so the only way I can tell is to try them on with some weight and try them. Some work. Some don't
BACK PANEL - I don't need a frame or frame sheet, even in my 45L pack. The Zoor has S shaped side panels and so long as I'm diligent in cinching up the load using the compression straps, which firms up the pack, it carries just fine, even with a heavy load. The Zoor does have a padded back panel and on a pack that size, I consider that a must have. My current "small" pack is an EMS Packable pack (25L) and it has no back panel. I have to use a lot more care in packing it so I don't get a water bottle in the ribs, but this also allows me to use it as a stuff sack/summit pack with my full sized pack. If I were to replace it with a dedicated day pack in the 25-35L range, I would lean toward a padded back panel, despite the weight penalty.
USE - My packs need to work for XC skiing. I use my smaller day pack for front country skiing and my larger pack for backcountry. Neither has side pocket to interfere with arm swing. My kids both have Kelty Redwing 32s for hiking (really excellent packs) but these wouldn't be comfortable for me when skiing due to their side pockets.
You gotten some great suggestions. Others to look at... The Jandd daypacks are insanely durable. The Mountainsmith Mayhem looks about right. The Granite Gear Virga 2 would be on my short list. The Kelty Redwing 32 and 45 are both worth close looks. I generally like the Gregory packs I've seen but I'm underwhelmed with the durability of Osperey packs as I've seen several blown out.