Through the years I’ve had all the 70s Roland SH synths, and have a lot of love for the series. Never owned a 101. Here’s a rundown of the 70s SHs, plus my opinion in one or two sentences:
SH-09: A killer little bass++ synth. Superb sound, very musical and with just the right amount of controls and versatility.
SH-1: The forerunner of the 09, just about identical soundwise though a tad less punchy (the AR env isn’t as choppy as the 09 VCA gate). Beautiful interface but the extra controls don’t really make it significantly more versatile than the 09.
SH-2: 09 with an extra VCO. Even though it lacks any intermodulation of the VCOs, the added power is significant. A superb little synth.
SH-3a: Intriguingly original/unique design and nicely warm and dark tone, but the single VCO, awful sounding envelopes and high noise floor killed this one for me.
SH-3: Never tried it, very rare. Identical to the 3a except it has the diode ladder filter from the SH-1000, instead of the transistor ladder of the 3a.
SH-5: A gem of a synth with a superb vintage oscillator tone and excellent low pass filter, in spite of a whole range of disappointments: the AR and preset envelopes are useless, the band pass and high pass modes of the VCF are useless and the extra BPF is nasal and annoying. Still a great synth though!
SH-7: Another gem. Just about the same basic sound as the SH-09/1/2, with a lot of added functions. Excellent ergonomics and a joy to use, with many unique functions This is the only SH synth I kept, and my personal favourite by far.
SH-1000: Semi-preset but with some control of basic parameters. In spite of its simplicity it sounds great wit a sweet oscillator tone and that nice diode ladder filter.
SH-2000: Preset synth with pressure sensitivity. I found this to sound anemic and sold it within a week. It has a Moog style ladder filter.
System-100. I’ve only had the the 102. Surprisingly simple for the price tag, but the low pass filter and VCO sound are top notch. Same circuitry and sound as the SH-5.
Conclusion: Don’t buy any of them at today’s silly prices, unless you can find a superb deal on an SH-2 or SH-09. There are great sounding and more affordable alternatives today.
CV/gate
The ones that don’t have CV/gate interfacing (3, 1000, 2000) can be modded. Other mods are fairly simple. I’ve had a cv in for the second VCO added to my 7, for independent/duophonic sequencer control of the VCOs.
Here’s a track I did exclusively with the SH-5 
Sequenced with the Octatrack, multitracked in Live.
Edit @chiasticon probably has some opinions on the matter too 