A buddy of mine has one and I think he said his flight time is around 7 to 10 minutes. If you looking for a good cheap field charger, I would go with the Hobbico Quick Field Charger MKII. It will do lithium batteries to, if you ever what to go with lithium batteries (you will get longer flying time). The only problem is, you will need a 12 volt battery to run the charger, it doesn't plug into the wall. You can buy a good charger/cycler that plugs into the wall, but they are a lot more money.
The wall charger that come with Blade are junk in my opinion, it takes way to long to charge.