Big wheels roll over stuff better. Full suspension helps in the rough stuff. So how does it work when you put them together? The KHS Flagstaff is a 29" wheeled full suspension bike for trail riding and endurance racing. KHS is known for having great valued bikes and they tend to get into new trends pretty quickly. The 29" wheeled mountain bikes are one of those trends they have gotten into and have done a good job. It started with a hard tail and then they added the Flagstaff.
With 3.5" of rear wheel travel, the Flagstaff is aimed at cross country riding but is burly enough for rougher trails. The stock build is a middle of the road mix of parts that are more aimed durability than light weight. If you want to make changes, especially to the wheels you can get it down into the 25 lb range but the bike comes stock around 30 lbs.
The frame is aluminum with a horst-link pivot with a rocker arm activated rear shock. This makes for a good pedaling design that when set-up correctly will put the power to the ground, without pedal induced bob. Because the 29" wheels tend to smooth out small bumps, you can set the suspension a little firmer for a faster machine without giving up any comfort. All the pivots have medium to large sealed cartridge bearings, increasing lateral stiffness and improving pivot durability. This adds a bit of weight but is worth it as the rear end of the frame won't flex excessively leading to ghost shifting and chain line issues. The Rockshox Reba fork and Monarch rear shock are a good match to the suspension design. Both are tune-able for various riding conditions. The Reba is my favorite 29" fork. It's easy to tune and they are super low maintenance. The weight of the fork is reasonable and the stiffness is good for most riders.
The geometry is balanced making for a quick handling bike that isn't twitchy. 29" are known for the stability that comes from bigger wheels and longer wheel base. The Flagstaff in confidence inspiring on technical terrain and steep downhills but is still an able climber. The biggest drawback ride wise is that it isn't a quick accelerating bike but part of that is the heavy stock wheels. A light set of race wheels and tires will go a long way towards improving that flaw. As it is the bike takes a little more effort to get up to speed but takes less effort to keep it there, especially on rooty terrain or loose uphills.
The complete bike is a good value the way it comes stock, with SRAM drivetrain, Hayes Stroker Ryde disc brakes and Truvativ finishing kit. With some upgrades this can go from a good trail bike to a fast endurance racing machine.