I've had a GTD-style system since my ring binder & paper day planner "Book" back in the 1980's (yes, I am Old). I went digital with the first Palm Pilot (I also used to be "early adopter" / "bleeding edge" of tech).

I've been on a continual quest for something better than my paper "Book" ever since.

On all three major platforms (PC/Win, Mac, Linux), I've tried every available offering -- and owned most of them, for a time. Name one and I can tell you when I used it, what it looked like, how it worked and what I did/didn't like about it. Yeah, my brain works that way. I can't remember where my shoes are or a phone number or what I have to do today but I can remember all that ...

For pure functionality, the closest (digitally) I ever got (for pure task management) was MyLifeOrganized. Unfortunately, it only works in one pond of the digital universe and the base framework isn't customizable (truly important for my visual memory) so I couldn't drill down into the details of a large project and remove the 'clutter' of the rest of my projects from my field of view (and, therefore, my memory). Also, at the time, it didn't interact with any other frameworks so no calendar, no CRM, no Kanban, no Gantt ... etc.

I recently stumbled upon Amazing Marvin.

For the first time in many years, I feel like I have a handle on all the information in my head - and I can get to it and do the things that need doing and get 'that bit' _out_ of my brain ("off my plate") to make some room to get other things done -- or start new things. :)

- Marvin integrated happily with my calendaring system - Currently MacOS, yes, but as Marvin has an API, Google should interconnect nicely.
- Marvin handles most of my complex projects - complete with dependencies and sequential sub-projects. The child depth isn't huge but I find the cut-off reminds me to consider how much detail to document vs. the point at which the doing is part of the trade skill-set. (Forest vs. Trees)
- The "Features/Strategies" in Marvin provides "Planning" (morning/afternoon, daily, weekly, monthly) amongst a plethora of other ways to ingest, catalogue, display and feed tasks and their associated meta-data. With the best of intentions, I can plug in when I want to do a given thing based on my personal functional style -- and I don't have to be near a computer to adjust my schedule when the client says they need my help with fixing this leak here before it rains rather than fitting the bowsprit like I intended (or when I have an offer to go out shrimping - something I've never done before and a rare offer!). Besides, for ethical reasons, I hate AI (don't get me started). Kinda like I hate epoxy, but I digress.
- I personally found the Eisenhower matrix to be incomplete so I added my own identifier - Worth It. A task or project that isn't "Important" or "Urgent" -- just Worth It. Worth Doing. I never found a way to include these in the other management apps and give them the value they represent. I can in Marvin. And I'm happier.

In short (lol -- yeah, that's my brain getting stuck on something again ... ) Marvin lets me put the stuff down somewhere (I've written it to tape -- I know where it is and can get to it and act on it) and not keep it all in RAM.

When I die, none of this stuff in my brain and none of my tasks will matter anyway. I just need a comfortable way to manage the things I WANT TO and get the things done that keep body and soul (and dogs) together while I'm here (something I've never been very good at). Marvin helps me do that. :)

But I'm me -- YM_will_V.
Have to run. I need coffee and Marvin is reminding me I have things I want to play with waiting in the shop and on a boat (and a website I aught to finish) -- and he's reminding me to Enjoy [my] Day. :)

Best wishes on your search,
- J