[FoRK] roomba?

[Jeff Bone]

Anybody here a Roomba owner?  I'm trying to figure out which model to  
buy (if any) and am somewhat confused by the product lines.  I can't  
tell if the 5x0 series or the 42x0 series is more recent;  the iRobot  
website only lists the 5x0 series and the flagship, 580, is more  
expensive than the Discovery SE 4210 by a longshot, but I can't seem  
to find a comparison of the two anywhere.  Amazon sells both...

Anyone?  Bueller?

jb