Well the tests have shown the 4 to only be marginally faster. Not worth it to me.
As has been already addressed, it's a LOT faster...100-150% improvement numbers in GPU, CPU, and memory performance. Twice to two and half times as fast...but, that said...and as you've noticed, with your iPad '3', you're missing nothing at this point in the game other than perceived speed increases in everyday tasking--app launching to spelling correction, browsing speeds or the time it takes to edit a photo/render a video. You're still able to use every piece of software in the App Store and utilize the latest iOS 'goodies'. Don't let it bug ya, don't get caught up in comparisons, etc. the iPad of early 2012 is still a worthy piece of gear and still the second best tab on the market!
You must be an iPad 3 owner. Feel a lot of iPad 3 owners post same or similar sentiments about iPad 4 owners who will be screwing themselves cause iPad 5 is so much better.
(I have owned all four iPads). Currently own. iPad 3 64GB LTE and just picked up iPad 4 64GB wifi.
I thought the exact same as I read some of these comments. I'm in the same boat as you and have the 64 LTE from earlier this year, a 32gb iPad 2, and still a 32 original iPad that's now the property of our seven year old son. We did the same, sold the '2' and bought the 4. I'm still going with the biggest storage option, but this is the first time I've bought without cellular option. I've got the iPhone 5 for tethering as well as a MiFi card...so this time, I may save the 130. I'm going to take the next two weeks to consider. As you, too came from the early '12 LTE version, are you certain you're going to stick with the wifi only? It's really a nice option and with the AT&T 'bucket plan' now, it's only $20 a month additional without the need to tether (and waste battery life). Just curious as you (& your family) seem to be enjoying your iPads the way we are!
J