I've played around with both Granite Gear Latitude Vapor (LV)and the Mountainsmith Ghost, and for me anyway, the Ghost is much quicker to pack and much easier to use. I find the LV's double zippers and myriad of side straps tedious.
The Ghost has truly usable side water bottle pockets that can easily accomodate 32L bottles or bladders — and unlike with the LV, you can easily pull out and put back water bottles without needing to take off your pack.
I really like the Ghost's bottom compression straps, because they enable me to strap my tent outside. When it's raining, it's a good thing to access the tent without needing to open up and rummage through the rest of the pack. And when striking camp, I can pack and zip up the Ghost under the protection of my tent, then take down the tent and attach it to the pack. The Ghost's bungee cord is great for storing my rain jacket. Rain jacket and tent aside, I prefer to store everything else inside my pack.
The GoLite Lite-Speed appears to be very similar to my beloved Ghost — except for the absence of bottom straps (which can be added pretty easily). However, the Lite-Speed does boast two hipbelt pockets that are actually sized to be usable. A big plus in my book.
Obviously, all the above reflect my own preferences. YMMV and in any case, whichever pack you pick, fit and comfort will be foremost.