I think Remember the Milk is a great tool for managing tasks and information. However, it depends on what the person is looking for. If you are looking for just a simple task management tool without any bells and whistles, this may be a lot, as it has a lot of advanced features (and even more if you go pro). If you are looking for a more robust task management tool with the option to add priorities, tags, categories, and assign tasks to others, this may be more suited for this. It is also helpful for managing lists like shopping lists or project lists.
It's great for everyday use, whether you adhere to the GTD regimen fully or just need a way to quickly capture and sort your tasks. However, it may be less suited if you're looking for a task manager that lets you collaborate with others or if you want to visualize your tasks in other ways, like a Gantt chart.
The interface of Things was good 10 years ago, and has been refined ever since. It's lightweight, while still being readable and showing just the information you need to see. Also, something I haven't seen in any other (of my) app(s) is the keyboard shortcut/launcher, where you start typing a letter, and a dropdown menu lets you quickly jump to a view.
Google Tasks is a much simpler task-keeping interface, and I use it for the most important tasks on my phone. It does not offer tags, priorities, or distinguish between lists/tasks. It does let me star tasks, but does not let me determine the priority levels. I can also move tasks to different lists, but they can be hard to manage if there are too many, so I generally do not use this feature. For me, Google Tasks is ideal for very simple "I need to write this down" type tasks that are of high priority. It is not a good brain dumping tool because tasks can easily get lost. This is more for those nagging tasks that I want to do and make sure there is an appropriate alarm for. It also integrates well with my Android home screen. However, when I have lots of tasks I want to categorize, or I do want to do more of a brain dump type thing, I think Remember the Milk is far better. I can have more control over priorities, tags, assigning tasks to others, and other robust features.
I've tried numerous to-do apps, some that never even go out of beta. But I kept returning to Things, mostly for the user experience. It's unobtrusive and fast to use, and it looks fantastic, which is more important than I first realized. To become more organized, my app of choice needs to look organized. Also, many competing solutions are trying to force you into one way of using their app, while Things feels more open to letting you define your way of working with task management.
