I'd say that if it does what you need it to, then yeah, it's worth the trouble.
I've had a list of comic books I'm looking for in my Palm for years, that way when I'm out somewhere and run across titles I'm interested in, I know which issues I don't have yet. I'm currently trying to get a complete run of the
Shogun Warriors title that Marvel put out in the ... '70s I think.
I'd think that the only real drawback would be that you can't adjust your list on the fly with a 505. The searching thing seems like it'd be fairly manageable with a good TOC plan.