Last week, my Everyday Backpack from Peak Design arrived. Since I wrote up a bit for it on the REI website, I figured I'd bout as well share my thoughts here. This is easily my favorite backpack for everyday use that I've ever owned. If you're trying to choose between the 20 & 30L versions, I'd recommend the 30L version unless you have a really small frame. The extra space goes a long way.

Love

Easy compartmentalization of the main pack space. This makes the whole bag usable, and easy to access, even when stuffed to the brim.
Sleek design, looks great on the back. The 30L version I have does not look oversized on a medium-frame person. (I'm 5'10", and it fits and looks great.)
Plenty of space for everything that you might want to bring with you.
No strings. While the bag comes with plenty of external straps that you can use to hook extra gear onto your pack, they all tuck neatly into convenient hidden pockets, so you don't have straps getting in the way.
The mag-latch. It's amazing, and I love it every time I use it.
The handy carry straps on the top and both sides are perfect for grabbing onto the pack from whichever way you want to.
Once you try a pack with side-access from both sides, there is no way that you'll ever want to return to a regular pack. Being able to get at an item in the bottom of your pack while still keeping the pack worn but sliding it around in front of you... it's amazing, and somewhat shocking that no other pack companies have brought this aspect of photography bags to an everyday backpack before.
The sheer number of additional carry straps and loops is fantastic.
How the bag feels on the back. It feels snug and secure, and doesn't move around awkwardly like some packs tend to do.
The thoughtfulness of including loops on all of the cinching webbing is awesome.

Less Love

I wish that Peak Design had used a bit more padding in the shoulder straps. They're not uncomfortable, but I've had much more comfort on other packs.
The clip systems used on the bag take some getting used to, but they do work well. The trade-off being made here vs. traditional clips is the right one, I think. Unlike traditional plastic clips, the aluminum ones used aren't prone to breakage.