This is a general, rather unstructured, reflection on my experiences with DEVONThink. Its only use may be to assist others who are considering buying a licence. To the other, well-versed, users here I apologise for reiterating what you will already know so well.
Background
I never knew what DEVONThink really was and the name always puzzled me. However I’d used the EasyFind app for many years and found it useful so one day, out of idle curiosity, I downloaded and installed the trial version of DEVONThink 2 (already then late in its life — although I did not know that at the time). I dabbled, explored, gazed alarmed at the licence prices, dithered…and finally decided to take the plunge and buy a licence. However, at virtually the same time as my decision DEVONThink 3 had been released so I had to purchase a version 3 licence (even more alarming). I bravely decided a Pro licence might be useful (perhaps I’d use OCR a little) so bit that particular bullet and paid.
Initial impressions
The layout of DEVONThink 3 helped me understand what the app was and how to use it. After all, it looked a little like a rather more sophisticated version of Finder. The excellent guide was initially slightly daunting but I slowly worked my way through it - simply ignoring the sections which, at that time, meant nothing to me. A “personal” database was set up with little effort (and probably little thought, at that stage).
What I have learned
The more you use DEVONThink the more useful it becomes.
The Pro licence is, without question, worth every penny I paid for it (apologies to those who count in other currencies). OCR and custom metadata are invaluable, as are the ability to import emails and the imprinter. My use of DEVONThink repays me daily. My collection of databases has expanded to include one for downloaded manuals and guides for software and devices (have you ever tried to remember to how program a watering system timer from one year to the next?), one for some old emails, one for AppleScript code snippets, one for 18,000+ diary entries exported from Day One…and others.
The guide (continuously updated even for minor version releases) and this support forum are, in my experience, unsurpassed. The forum is more than merely tolerant of naivety and I have benefitted from much virtual hand-holding through the years.
It is crucially important to me (even more so now I actually appreciate it!) that my data is stored, untouched in its original format, in DEVONThink and can be exported with ease (either individually or in bulk) any time I wish.
I love smart rules and have achieved much with them. However, guided by the patience of others, DEVONThink - and in particular the forum - have encouraged me to dabble in AppleScript, which I have also very much enjoyed.
More recently I have explored markdown (which I had previously used only to a limited extent) and the recent markdown enhancements in DEVONThink have easily persuaded me to use it much more. I am strongly attracted by the fact that it’s essentially plain text and not some proprietary format.
The developers of DEVONThink seem to have a philosophy with which I strongly identify - not only in terms of security of and access to data but also in terms of the way they support their product.
I hope all of this does not sound sycophantic. I merely wish to:
thank the developers for a superb product;
show some appreciation for all here who have helped and guided me from time to time; and
encourage others who may at some time be considering dipping their toes into the DEVONThink waters.
I would add my voice to this, very well said @Stephen_C. It’s sometimes quite hard to explain to non-users the value of DEVONthink, but I think you’ve nailed a good rule of thumb for good software, namely the more you put into it, the more you get out of it. That applies to both adding data, but also time spent exploring its features and extracting more use out of it. I would add Tinderbox and TheBrain to the list of tools that fit that description. Long may they thrive.
I subscribe to every single element of these experiences. On top of that, it’s getting better all the time. I would add
(8.) The recent update of the Evernote export / import feature (the one where Evernote links are converted to DNT links) has prompted me to reimport 100 GB of Evernote data (starting from 2004) with ease, stored nicely in a separate DNT databases for access in case I need it.
For myself, Applescript is a must have feature
I’m impressed at Devonthink’s support for scripting, and that it’s so integrated into the product’s core
I was an Evernote refugee, in shock that they dropped scripting support
I’m also grateful that Devonthink so seamlessly imported my data collection
data is stored, untouched in its original format
I also appreciate the native format storage/access
markdown
I’m not a markdown fan, but I appreciate that Devonthink supports various editor/formats,
including html (formatted note); I use an external text editor if I need to access the code
Yes. This. All three, but especially that first one.
EVERY time I provided feedback on EN v10 and of every single survey I got from EN after leaving I put the loss of Applescript support as my first comment.
And the responsiveness of support here. I’ve used no other software with this level of responsiveness to questions and feedback.
I am leaving EN for kinda the same reason. v10 is electron garbage that doesn’t take advantage of the power automation and features of the operating system its running on. I stuck with EN because it was cross platform but I’ll deal with that inconvenience if it means a more powerful app. Time to learn DT
I am leaving EN. v10 is not only electron garbage, things just didn’t work as expected. Many things used to be working is also no longer working. So, I am still using EN Legacy. I am in the midst of moving my notes/data from EN to DT. Only a few weeks into DT. So much to learn. So mush possibilities to get things done.
Not forgetting the huge knowledge that we can search in this forum. The responsive help we can get in this forum. I am very happy that I made the move.
A really great write-up @Stephen_C. I’ve used DT for a little over 18 months now, and still learn how to do things on it weekly. This forum, is inspensible. I’ve answered a ton of questions just by searching on here (usually by checking the “in titles only” option).
Though not a member of the DEVONthink staff, it was that guide you refer to, that ultimately enticed me to buy this program. Joe’s hypothetical scenario to help explain DT’s "See Also functionality involved Steve Martin and a banjo. After reading that specific function, I realized I had to get my hands on this software—which has proven to be worth every penny.
I wrote Joe after buying DT to give him some feedback. His “take control” guide for DT3 was brilliantly constructed. I still rely on it often.
I identify wholeheartedly with what you have so kindly written 
