I feel the same way about my X3. It's still on the firmware it came with but it also suits my needs just fine so don't see a need to update. I'm getting my DX50 tomorrow in the mail and bought a 64gb sdxc so I could also test it out with the X3 to see how that works with it. I bought one of those card readers too and it's so much faster than my laptop reader. I don't think I would have the patience for 2 hours to fill up the 64 gb card.
Wow would love to get your comparisons of the X3 vs DX50.