I know there is a difference in the styles of these two 21.2cc trimmers, but i was wondering why echo made the 2100 series and the 210 series. Is one cheaper then the other? Is the 2100 series a HD product made for them by Echo? I have the SRM210 that i bought off a local dealer and i just got one from a garage sale at a great price. I thought i was buying the 210 and when i really checked it out it was a 2100. Any thoughts?