Dave - I learned how to play the same way you did. And I've been suprised at some of the tab requests I've seen over the years - I've often thought "Why didn't they just try to work it out themselves"? However I'm still tempted to learn how to use the tab system but I can't imagine being so tied to it that it becomes a crutch. After awhile you just need to learn how to use your ears. Just my opinion.

Being able to play be ear really came in handy when I used to play regularly with a guy who had the nasty habit of starting off songs in different keys than we had rehearsed them in.