I've been using MLO for about a year now, which is the longest I have ever stuck with a single software title for GTD. Its not going to be everything to everybody (duh!), but it does quite a job of being good at what it does.

Advantages that keep me coming back:

• Can be very quick to add new items/projects once you have the outline setup
• Outline format makes it easier to see where you are and how a particular task/project/goal fits into the big picture (compared to a non-outlined format like outlook)
• The Outlook sync keeps the data from being ony available in one place. There is quite a bit of controversy around this, but for me, the Outlook sync means that I can have access to my tasks in many ways that I wouldn't expect MLO to afford me (ie, sync to online service). [See note below as well]
• The recurrence setup is quite helpful when you have defined sets of tasks that always need to get done. For those unfamiliar, you can set tasks to recur on many different schedules, and child tasks inherit the recurrence of parent tasks, and even support modified versions of that schedule (ie, child is due 2 days before the parent). Pretty powerful, but it does require some exploration and setup time.
• Pretty active development. In the past year, we've seen many minor version updates, and betas are frequently released on the Google Group ahead of time. The developer is wonderfully responsive in general. He even publishes a feature list with approved, considered, done, rejected features.
• Quick entry box available by system-wide hotkey
• There is a PPC version and eventually will be ActiveSync support (not released to the public yet). I can't vouch for this one though.
• The program is as stable as just about any app I've ever run. This is a big plus when you get down to it. I can't remember a single time that MLO crashed on my system.
• Customizeable printing if you want to get into the details of the HTML template.
• A nifty Zoom feature that lets you zero in on one area of your outline, and makes the rest of the tasks go away. Great for concentrating on one project/client/life area at a time.
• The application is pretty quick. I only mention this after trying Achieve Planner, which had a lot of features, but the application itself slowed down my thought process as I waited for it to catch up. Outlook has suffered the same problem on occasion.

There are a few issues that still need to be resolved, and most have been put on the table and are at minimum under consideration by the developer. To be fair in this review, here's some:

• The computed-score priority method apparently needs tweaking. I personally have never really seen anything bad, but I don't pay too much attention to the way MLO ordered my lists
• Due dates and start dates are an inseperable pair. By this, I mean one must always have the other. I personally really want start dates without due dates, and others lobby hard for due dates without start dates.
• Related, the start-date defaults to the same as the due date. Hate this behavior because you have to remember to change two dates.
• Needs a multi-column outline view. This has been talked about quite a bit, and is somewhere in the works we hope. A lot of features will cascade from this, like filtering. Basically, right now, the outline view shows the task only. To see extended information, you must click on the task and view it in the Properties pane. The idea of the multi-column view would be that certain columns would be always available.
• My personal vendetta, though not many seem to share insistence on this one: the ability to see the Notes page and the Properties page at the same time. Right now they share a screen location and you must switch tabs between them. I use the notes a lot, so I want to see them separated.
• No VERY quick way to tag a few tasks for something

Now, I'm sure there are more pros and cons I'm forgetting about, but lets face it, this little mini-review is just a reason for me not to start working yet. However, I will add this:

I use the Outlook sync to overcome a few of the limitations above. The Outlook sync is very powerful, but takes some getting used to and testing. Its highly recommended to try it out on backup copies of data in both programs. What *I* do is keep my MLO tasks in Sync with Outlook, and then setup Outlook views that display the user-defined fields that MLO adds (like MLOProject). I can get group/sort on these, and they are displayed in a multi-column format. I also use Outlook's priority indicator to select my 'goal' tasks for the day (I don't sync MLO priority to them).

If you haven't tried it, I'd take a look. Its not for everyone, but it does have a good set of features, is quick to use, and has a bright future. The Google Group is active and very helpful, and there is a Wiki with some other suggestions.

Daniel