I ordered the Posey 2 bag from Kelly Moore first. I wanted a bag that was just big enough for my equipment, and I didn't want my stuff floating around in there. I was convinced that the Posey 2 would be just right.
Well... it was a bit on the small side. It fits my old Nikon D90 with kit lens and 50mm 1.8 lens perfectly, but was a bit of a squeeze for my Nikon D700. I highly recommend this bag if you have a smaller camera body.
The things I loved about this bag in particular: the color... beautiful warm grey. The organization pocket... it's pretty awesome. There are lots of pockets and zippers on this bag, and even some kind of hidden pockets, which can be a great thing.
I also love the beautiful purple interior color that all the Kelly Moore girl bags have. It's a fun surprise, especially if you choose a more conservative outer color like I did. I love the zippers. They have a very satisfying sound to them, and feel very sturdy. The KM bags are also less bulky than the Epiphanie bags, which can be a good thing if you are wearing them around and want them to lay closer to your body.
I decided I needed something a bit bigger, so after hours of research and reading every review I could find I finally settled on the Epiphanie Stella bag in Slate Blue. I thought the dimensions sounded good, I liked how it looked, and I liked all the outside divider pockets. I'll start off by saying that I LOVE it! Whew! I was so worried that it wouldn't be the perfect thing again.
It looks different colors in every light (as evidenced by my completely unedited photos below). My sis-in-law saw it twice and was surprised the second time because she could have sworn that it was grey the first time she saw it. It looks grey in some lights, sometimes blue, and sometimes purple. I love it, and don't mind that it's ever-changing. I guess I am too, so it suits me. :)
It's wider than the Kelly Moore bags, which means it doesn't lay as flat against the body, but I like the way the camera is situated in it better. The Epiphanie is definitely more padded and protective (and the shoulder strap is also more padded). It took me awhile to figure out how to configure the dividers inside, but I think I figured out a pretty great way to arrange everything. I have my Nikon D700, 85mm 1.4, 50mm 1.4, lens hoods, and some extra space for my notebook, phone, CF cards, lens cleaner, keys, gum, chapstick, etc. I like that it is shorter and wider... more open... so it's easy to see all my gear at once when I unzip it. I don't have to dig down in a bag. That said, if I got caught in a rainstorm, it isn't as protective as the KM, because even when fully zipped, it still has holes at the side.
So, in a nutshell: both bags are great... it just depends on your preference... what style you like, if you prefer more sleek and less padding and function, or more protection and function, but more bulk. Let me know if you have any questions! I hope my research and experience can help someone else make the decision. :)
UPDATE as of July 20, 2012: I absolutely ADORE my Ephiphanie Stella bag... I get compliments constantly on it, I love carrying it around on shoots, and I haven't found one thing I don't love about it. It doesn't feel overly bulky, as I feared, and looks good on my shoulder. It is easy to set down on the ground right by me while I'm shooting (doesn't tip over), and it's even okay to keep on my shoulder AS I'm shooting if the conditions aren't good to set it down. I love how my camera fits in the bag, and it's so easy to access everything I need. The size is perfect... I could put a few more things in there if I needed to, but my equipment isn't swimming around in there. It's comfortable on my shoulder, and I still, after a month and a half, can't stop looking at it. I was slightly disappointed when I ordered, because they had discontinued using the brightly colored interior fabric, but I got over that disappointment quickly. The whole bag looks great, inside and out... have I mentioned yet that I love it?? :)