How'd you choose your username? The 2600 is a "GS2" 

It can do all sorts of stuff, just older and slower than some of the current or more recent screens. Yield monitoring, auto steer, planter clutches, sprayer stuff, etc

You can still get RTK or SF1 (free but better than WAAS) on the SF3000. Both can be had for pretty cheap now since they're a few generations old