I've been using iGTD for about 6 months now and recommend it. The program is loaded with cool and useful features. Try out the f-key data entry tricks. I'll bet at least one will impress you. I have depended on the .mac syncing feature to manage a single GTD document on my laptop and work computer and it has worked well. The system is simple, iGTD syncs to .mac when it quits, but has been reliable. I have avoided ical syncing because of worries about my calendar data. Sounds like that might have been a good idea. Entering data seems to have become more buggy with the latest version. I always seem to be getting extra "new events" pasted into my list whether I hit tab or return or enter. Overall the solo developer is giving us an amazing product for free! Thanks.