The 4800 is plenty big for me to do four days in. If you tend to be a maximalist rather than minimalist then get the 6300. For 2014 we're offering the 6300 as a roll top as well as a drawstring.
Yes, you can strap an additional dry bag, bear can, or whatever on the outside of the 4800. The most common places to strap stuff is under the bag compressed with the load shelf, under the talon on the front of the bag, or on top of the bag using over the top straps.
I didn't take a photo of the 6300 in daypack mode because it would have been redundant. It compresses down as small as the 4800. The Talon really sucks an empty pack bag up and controls it so it doesn't flop around and annoy you. It works well for that.
In those pictures I've got one of the first Day Talons. The newer Day Talons look a bit more refined with zipper garages, etc. We don't have good photos of the bigger Talon yet.
