I don't think you can really go too big, and I'd suggest a 6900. I ran it on a 10 day mountain goat hunt, and even though we lost a few days due to weather it was pretty dang full and I think I would've struggled fitting gear for 7 days in a 5900. Not saying it couldn't be done, just that the extra space in the 6900 made it easier.
Beyond that, the bag is so compressible that I don't see how you'll even notice any extra size in a "day pack" type mode. In fact, I'm headed to Kodiak for a boat based blacktail hunt in November and I fully plan on running my X-curve with the 6900 as a day pack (with the lid removed). I bought a Kiowa that I thought about running, but the weight penalty for the X-curve/6900 is IMO negligible, the size difference between the two when the bag is compressed is also negligible, and the X-curve/6900 provides so much more in the way of capabilities than the Kiowa that it became a fairly easy choice.
Long story short...I'd go big
There is currently a SG xcurve for sale in the classifieds with a sky 5100. It's that an older model or a misprint? If it is older, were people just looking for a bigger bag like you mention?
5900. Take the lid off and it’s down to more like 4000. Compression straps help you get it even smaller if you want.
Do you have a sky 5900?The lid is 500, not 1900....
Do you have a sky 5900?
They all do. But when you take the lid off you’re right the pack has 5400 ci of capacity. But you roll the snow collar down so it can be buckled closed which makes the pack probably a foot shorter. I’ve never taken the lid off and just left the top extended as wellMy wife does, it has the standard 500ci lid.
I have the 5100. It’s very similar to the 6900 minus the side pockets. It really doesn’t seem much smaller in the main bag. 5100 zipper is a little shorter. 5100 has four little internal slots just inside the zipper, pretty handy honestly for little things.
Is the 5100 compatible with all of the current accessory packs and lids? I would think they wouldn't change the straps but I don't actually know.
Thanks!
I had the 6900 originally and the 5100 I currently have is definitely identical with how it attaches to the frame. Straps and lid connections are also the same. I don’t see why the access bag couldn’t be clipped in. There’s also the internal attachment points for the camp pocket, hydro sleeve.
That's great to hear. What made you go down in size? I've been going back and forth on their 5900 and 6900 but would be open to used as well.