I don't miss selling any analog gear at all. I think if you do then that is a state of mind and can be easily changed. Don't forget it breaks down, getting harder to fix, uses a lot of power, gets hot and can be seriously annoying!
One thing though is that if you are one of the older ones like myself who only had the hardware because that is what all there was, you do learn the principles of synth programming rather well and quite deeply. Especially if you had a modular synth and needed an hour or so to get the sound you are after. Practical hardware experience translates rather well over to VST's now. I was also an electronics engineer in a former life and I specialised in analog designs and stuff so that sort of helps too when programming sounds. It makes you think conceptually and out of the box in terms of coming up with very deep and complex synth patches.
I have got a couple of private students who want to learn synth programming and I have to do it from an all virtual point of view which looks like it could be a challenge.
At first the VST's that came out did not sound that great and the hardware beasts killed them dead. Things like a complete Oberheim setup with sequencer, drum machine, polyphonic and monophonic synth beasts. All that early analog gear I had shook the floor in a certain way! The first VST's were not doing that.
But things have changed and I really believe we are at a point now where the virtual instruments are just jaw dropping in sound quality and now the floor shakes just like it did years ago. I am hearing awesome fat sounding instruments. They don't overpower the hardware though. After many weeks say working in a virtual world I fire up the Kurzweil K2000 or the Roland JD800 and marvel at how ridiculous they sound and how big they sound too. I am having a reuniting love affair with my EMU samplers and OMG they sound good.
In the old days I found hardware analog synths to have quite a different sonic signature. Hence the reason some of us collected Yamaha, Roland, Moog, Sequential etc..and certainly when the digital synths also came out in the early 80's. In 1980 I wanted to be able to sequence different manufacturers instruments but could not do it easily. Having something like the Oberheim
'The System' was good but everything came out Oberheim sounding and too much of one thing is not great. I was relieved when midi came about because it basically allowed that different manufacturer thing to happen immediately and I did it straight up. The VST's now I am finding are also bearing their own very distinct sonic signature and you can combine different VST's in various combinations now and still hear the blend of different sounding VST's you may be after.
I did a lot of knob twiddling back in the old days too and even had others in there all doing it at the same time. I could even patch up my whole studio to randomly play for hours by itself! And you could move knobs around while it was doing it. I often had long experimental periods doing that and recording it all as well. I don't think that have left that out either. Great DAW software makes it easy to map controllers to any software and synth parameter. Studio One excels in this area, it is painless and fast to setup a controller to the instrument for example. There is plenty of scope for performance controller stuff to be added either to existing sequences or totally live while you play now. We have got more control I believe over synth parameters than ever before too. Check out Alchemy's mix pads where 8 synth parameters can all be linked in a way that was impossible previously as well. I used to get 4 people with two hands each to attempt to manipulate 8 synth parameters on say a modular synth. But now it can be done so easily. There is great software for music to be generated in random ways and do interesting things now as well. That has all moved on.
Most of all I am impressed at how they can now invent an instrument and create something that previously would have cost the earth and filled a floor of a building. Something like Native 'Prism'
(As well as many others of course) for example is one hell of an instrument and it sounds amazing too. What is going on inside that beast is incredible. They can now add features, change things around with subsequent updates etc.. Do things in software that was virtually impossible to do any other way. Korg for example have improved their M1 and Wavestation in their plugins. The latest and the best of those two instruments now exist only in the software. And man they sound huge.