I quickly ran a few tests, compared the 3 to the 4 and found this. 1) Wifi Connection rate iPad 3 = 65mbs iPad 4 = 150mbs 2) Wifi File Copy from Server on LAN iPad 3 = 82 sec iPad 4 = 51 sec 3) iMovie Render 1080P 30 seconds of pan and zoom photos with music and fades iPad 3 = 31sec iPad 4 = 28 sec 4) Web Page loading The iPad 4 is faster every time loading pages. 5) Screen Quality Both look very similar, slight different color temp with the 4 being warmer than the 3. Was just quick test of my existing iPad 3 as is, vs the out of box 4 so keep that in mind. Hope it helps you decide. I like seeing the faster Wifi speeds. You'll need a dual stream router to gain from it. Disappointed the iMovie render did not change much. Is it worth upgrading ... For most probably best keeping the 3 for now and upgrading a down the road to the 5 or 6. Especially true, if you have spent on accessories for the old connector. The retina 3 is pretty nice and is under valued in the resale market right now. If your buying new, lucky you, I'd go for the 4.