Do you frequent
www.mtbr.com? A great mountain biking forum. They have a section on Mongoose-Schwinn bikes.
http://forums.mtbr.com/forumdisplay.php?f=137I'm partial to Rocky Mountain bikes -- the geometry works for me -- and have a couple Rocky Mountain Vertex 30's. I keep a third bike for friends -- K2 Zed 3.0 All hardtails. Sounds like we ride milder trails. I use one of my Rocky Mountains for bikejoring.
A Topeak Aero saddle pack works for my bike tool, leatherman and some first aid items. I also always carry a Camelbak -- the Alpine Explorer, to be specific, with 100 oz bladder.
And for my dog as she ages, I just bought a Croozer dog trailer.
Good luck with your bike search.