I have an ATV3, and a jailbroken ATV2 with ATV flash. I prefer my ATV3, using Plex with either my Iphone or Ipad. The Plex interface is so much better, and more reliable, than the ATV flash media player on ATV2. There really isn't anything I can do on my jailbroken ATV2 that I can't accomplish with ATV3. HBOGO is now airplay compatible, Showtime should follow shortly. And, of course, the menus are snappier on the ATV faster processor) and its 1080 v 780. if I wasn't so lazy, I'd sell the ATV2 on Ebay, buy another ATV3, and pocket the difference.
While I don't disagree with you, many people do not have an iPhone or iPad to airplay videos to their appletv3. It also add another layer of complication for troubleshooting if you ever have issues.
I wish I could just get Plex as a native app for AppleTV and call it a day. I'd pay $15-20 for it. Cmon apple work with us here!