The ad-hoc thing is really nice for teams that seem to form spontanteously : Read as StartupWeekend, Hackathon, etc. But probably not for firmly established teams that have protocols and ways of working that are already formalized in project documentation and tools they've been using.

A todo list should definitely get out of your way (for the MOST part), but be intrusive enough that it helps you get the work done to be meaningfully differentiated. (just a personal opinion).

Keep trucking, I think this is a good tool for ad-hoc team task lists, and I'm sure you'll come up with some good use cases for that specific function.

And most importantly, don't let the nay-sayers get you down :-)