I can recommend the 296. As presbyopia sets in, I find colour displays much more legible than monochrome ones, and most of the extra functionality of the 496 that I need has been catered for by downloads from
here. I've got the optional auto kit as well, which is really nice when you're sightseeing from the air, because you can identify every little village you pass over, and zoom in to street level if you want to.
You can use Garmin's MapSource program on your PC to load and save routes, waypoints and flight logs, and Garmin have a free SDK, if you want to program the device yourself.
There must be better user interfaces around, but it's logically consistent, once you get the hang of it (which will come easily if you're familiar with the GNS430/530).