[Weasel]

I like:
• parallel and consecutive projects
• nice interface, easy to learn
• selecting a context shows also task in sub-contexts
• nesting of tasks

I dislike:
• no priorities
• filtering is not obvious (need visual clues)
• not enough options to customize interface (column with, position etc.)
• no visual clue for recurring items
• items ticked off disappear immediately
• difference between folders-projects-tasks

There are probably a few more things, but that's what I can think of momentarily.