The only reason to keep ios 5 would be if you were a developer and needed it for testing. Most current apps don't support 5. If you don't update to 7 you will be forced to 8 in a month or so. The ipad 3 will be a lot faster and better on ios 7. It's by far there best os. I've been running an ipad 3 with ios 7 since beta versions and it works fantastic. I'm about to update to ios 8. The ipad 3 is the cut off for ios 8 support. So it's still a very capable machine. But ios 5 is rubbish compared to anything greater than 5. Nobody writes apps for 5 these days because there were such major changes to the os in 6 that it's not worth it for the few percent of people who still run this legacy os. Ios 7 is a brilliant os.