The question is: what is no worth keeping any more, what can I replace with the other gear I already have and what can be replaced with software synths?
I'm an old school guy who started playing in the late 80s, so I'm all into MIDI sequencing, hardware synths, drum machines and samplers -and with no recording gear; doing it all in one take (and recording it to a casette deck).
Of course with DAWs everything has changed (I no longer need to play everything in one take), but I'm still struggling to figure out where to start with all that. With so much gear I'm going to run everything into a 48-input line mixer, then repatch when recording into the DAW. I have some cheapo hardware effects (Alesis Quadraverb 2, Behringer virtualizer, ART SGE Mach II), but think I might use those just for composing (in hardware), then add (better quality) software effects to the tracks when recording. So that's my setup. Now for the gear I'm considering selling:
Yamaha TX-81z
I know this is a "classic", but do I really need it when I already have a DX-7 (1st. generation and a TX-802 which so far are keepers)? I know it's got different waveforms, so in case it's irreplaceable, what kind of sounds exactly are unique to it? I've always seen it as a cheap alternative to a DX-7, not something totally unique.
Roland D-110
How does this synth stand today? It's not quite a D-50, and there are loads of software instrument ROMplers out there. And multi-timbrality isn't as necessary now as it was back in the day. Would you keep it?
Roland JX-8P
Am I crazy for considering to get rid of this?

I have to add that I have an MKS-70 (which I want to keep) as well as the programmer for it (I suppose most of the programming can be done with an iPad or computer editor these days, but real knobs are still something else).
I haven't yet had time to really get to know the MKS-70 inside and out, and my first impression is that the JX-8P is more "instant" at programming while the MKS-70 is a little more cumbersome, but that might just be because I haven't read the manual properly or gotten the hang of it.
Yamaha DX-7 (1st generation)
Sure it's cool to have the original DX-7, and I do love its keyboard (it's nice as a master controller despite velocity only going up to 100 and not 127), but I do have a TX-802. On the other hand, if I sell the JX-8P I will need a master keyboard and if I do buy the keyboard-synth of my dreams (Sequential Prophet 6) it'll be nice to have a 5-octave keyboard....
Roland MKS-50
I'm really unsure about this one. I haven't used it much so I'm not quite sure firsthand what it's capable of but I understand it's a bread 'n butter type analog synth good for just about everything within the warm, analog territory. In the category of the popular Juno 6, 60, 106 synths. Is it really that unique, or do I already have what it can do in the MKS-70, and for bass: my Studio Electronics SE-1 (which I bought to replace my Minimoog)?
Roland SH-101
Again, am I crazy for thinking about letting it go? Maybe... it is a very versatile synth with its built-in sequencer (great for syncing to my TR-808), arpeggiator and "instant" satisfaction with its sliders and knobs, but is it really so unique that I need it?
If I get an SCI Prophet 6, could that replace it (and more)?
Yamaha TX-16W
I know people no longer mess around with 3.5" floppy disks these days (but those can be replaced with floppy disk emulators). Apart from that I understand that the playback technique is completely different in software samplers or even more modern hardware samplers, and I might be saying goodbye to something unique and better sounding. True or not?