AU vs. VST2 and VST3? Which is 'better'?

[Citizen]

Is there any reason to choose one version of a plug in over another when you have multiple options in your folder? (I'm on Mac, Live 12 it it makes any difference)

I've never been able to find a definitive answer on this. (and kinda get sick of seeing all the duplicates in my Library, and when browsing Push)

Also, is it safe to delete the VST2 versions if you have VST3 versions — or will this cause problems if I go to open up an older project that uses the VST2 version?

[chapelier fou]

Do not delete the VST2 because, in my experience, they are not easily replaced with their VST3 version without losing parameter settings.
I’d love to be wrong, though !

[Calagan]

It's not an educated answer, but I found lately that I prefer to have vst3 versions instead of AU or vst2.
It was not like that before (say, 5 years ago), but now I find I prefer "most of the time" the vst3 versions : they are reliable, work fine, and offer more features.

Just a stupid exemple, vst3 provide the real value of each parameter for automation. Not AU nor vst2.

Another reason why to prefer the vst3 version to the vst2 : the vst2 will disappear little by little. U-He started recently to provide only vst3 updates to its synths. Because of Steinberg not giving anymore new licenses for vst2, they will slowly disappear.

[yur2die4]

I usually go with vst3. I’m not wildly experienced though. The only pesky aspect of vst3 is that its handling of Program Change is not always desirable. If I intend to do Program Change, I’ll load the AU version.

Edit: I think I recall some of the routing options being limited in AU though.
I wonder if anyone has made any YouTube vids on the differences between vst3 and au ?

[Muze]

I tend to go with VST3 because it's the most widely used for more modern plugins. But I would prefer CLAP

[Rivanni]

I tend to go with VST3 because it's the most widely used for more modern plugins. But I would prefer CLAP

If 'widely used' is your criteria, why prefer CLAP?