Conclusion: TurboTax Deluxe is an exceptionally well-designed tax preparation site that makes the annual chore of filing almost pleasurable. But it's missing many forms and schedules, and it lets random individuals answer critical IRS-related questions. It's also expensive.
Pros: Outstanding user interface. Very good top-level help. Excellent navigational system.
Cons: No Schedules C, D, or E. Also missing others. Support website, linked to by the main tax prep site, allows responses from anyone. Expensive.