I use PiRAWhna and iPhoto mainly, both very good!
The iPad 1 is still great, my OH inherited mine when I bought the iPad 3 and it's still going strong!
iPad 1 is indeed more than adequate for what I require - yes I would like the higher res screen, but not worth the upgrade. I'm just peeved with not being able to use iPhoto and seeing a speed decrease over the last 6 months for no apparent reason :|