I am still using mine too. A 64GB 3g bought on launch day (a little later here in Japan due to the earthquake.)
Like most, iOS5 wasn't a good idea, it reduced it to a buggy crashy mess.
It was almost unusable so I updated to a mini v1.
I then reinstalled the os and turned off all the bells and whistles and it is usable for most things. Web browsing (I have Java script turned off) and air video are the main uses. The bigger screen is a nice thing to have.
Some less demanding games run pretty well.
Actually since installing iOS8 on my mini they seem to run about the same speed! If I was a paranoid man, I may suggest there was a plan behind all this..
If you turn off notifications, iCloud, java script it doesn't run 'that' badly..although it does limit its use somewhat.
I still get about 8-10 hours out of the battery, and will probably continue to use it until it dies, I feel I got my moneys worth anyway.