I find that's another aspect that is highly over eggarated. Almost all apps nowadays are written for V2.1 and higher in which the apps all perfom well across the three different software version and are all compatible, barring any hardware limitations ie camera's etc.
and with over 90% of all Android phones running on 2.1 and higher these claims seem rather outdated.
http://www.eurodroid.com/2011/05/sta...-66-of-phones/