Reason I haven't upgraded to 3x yet. PSPI don't work, takes a rocket scientist, apparently, to get resynthesizer to work based on threads I see. Not even sure if Mathmap works in 3 (didn't do any research on that one, but I suspect it does not; just a hunch). Haven't really seen any features in GIMP3 that compels me to install it. Thought about downloading the no-install version, but, like I said, just thought. lol

Sorry for my spiel; has nothing to do with the developers really; just my taste. I know there's a lot of good with the new GIMP, but I guess I'm very set in my ways at the moment. Anyone want to safely share their spiel, I wouldn't mind hearing your thoughts as well. Sometimes you just have to push such things off your chest.

I get what you are stating Lyle. I Just installed them both. I will always have Gimp-2 installed on my machine.
I do love the FX and new vector layers in Gimp-3 though and there is talk of re working the path tool to include shapes.
I think possibly the reason most of the older plug-ins won't be re-written is because the original code writers are either gone or no longer interested in those projects. Actually it seems most everyone isn't. I have re coded only one of my own scripts "Embroider Stitcher"and then lost interest. LOL
But Resynth, and a few others such as shellout for certain programs have been finished for 3.0 and do work well.
As well as AI being introduced first into Gimp-2 and then coded by Ikks for Gimp-3.
In fact MareroQ has written a plugin to call Gimp-2 from Gimp-3. So you can work in Gimp-3 and transfer files to Gimp-2

The only problem is you can not open those XCF workspace files in Gimp-2 once they have been saved in Gimp-3.
It looks like future down the road Gimp will be able to record GEGL, Actions, and other functions. Possibly with the ability to save the action as a coded script or plugin to be used by any user. Macros! That will be cool.

Some day i will sit down and recode some of my favorite SCM scripts. Such as Chewed Text and Lizard Breath. That's another thing as well. If your SCM calls for another plugin written for Gimp-2 such as Layer Effects, it is going to be very hard to re write those plugins, and or SCM files. Some of my SCM plugins call Layer Effects and i woulldn't be able to use it unless i re write the Layer Effects SCM itself first.

I'll get back with you sometime next year when I believe I'll finally break down, Rod. lol

I don't think MathMap will ever work on Gimp 3. It was coded for GTK2 and Gimp 3 is built with GTK3. Also MathMap was developed over years by a whole team who have all moved on.

In some ways Gimp3 is a fresh start. I like making art today but I don't want to go back to school to do it
One of the things I use Gimp for is loading fractal renders of a thousand or more JPGs. I open as layers and export as PNGs which I can open in davinci resolve. JPGs render much faster than PNGs so using Gimp actually saves electricity which is now expensive in Australia. With a python script I can do this easily. It has not been coded for Gimp3.

Many of us are reacting badly to new tech. I often drive a diesel vehicle that has no oil level dipstick. I enter a service menu on the steering wheel to see a display of the oil level. Personally I think this is a step backwards. GET YOUR HANDS DIRTY I recon

I saw a prediction recently that most coding will soon be done by AI. I don't think I want that.

I remember the conflicts upgrading from 1x to 2x and then withing the 2x family, 2.2, 2.4, 2.6, 2.8 and 2.10x, very distruptive but still didn't seem like the filters all weren't abandoned; just upgraded to work in 2x. I know there's been effort for Resynthesizer and definitely with G'MIC, but not sure any of my other favorites like Userfilter and PSPI not to mention Mathmap will ever be migrated. I know these filters aren't important for most, but they are for me. Don't really want to use Shellout like plugins to run GIMP 2.10x filters within GIMP 3.x. Just hope 2.10X gets some loving if needed and continued support in G'MIC. Likely will soon try samj's portable versions for GIMP 3.0x soon, but don't feel comfortable installing GIMP3.x outright since I don't want my Windows Registry to go wacky like it had for past versions of GIMP when installing the major GIMP versions like 2.6 to 2.8 for instance. I guess I'm at a point where if it ain't broken, then don't fix it. lol

I am still using GIMP 2.10.38 (PandaJim) because I have a number of Python 2.x plug-ins I have written which I frequently use. Nothing sophisticated, but they save time when processing photos.
Also I have not upgraded from Ubuntu 20.04, as I have a set-up which is stable and I have no wish to change that!

I'm using mostly 2.10.38 on MX without python plug-ins. Been playing now and then with 3, but only after the biggest bugs have been swept off I will begin moving my butt permanently from 2.10 universe to 3.x universe. Bit by bit slowly, with multiple backups, hand phaser and a thorough evacuation plan just in case. Talking about versions, the last 2.8 versions were my favorite. Was easy to set up fast.