I first got an ESX-1 as I needed as sampler for playing backing sounds / loops live - that was a lot of fun but a little limited, and a fellow band member brought a Monomachine and the ESX became largely redundant or at least sidelined as we moved more into blast beats.
In the meantime, I decided that the EMX-1 looked interesting and I found one at a good price on eBay (the seller even agreed to stick it in a taxi and send it to me that way!) and it sort of blew my mind how good it was. the sequencer in particular is so immediate, and has plenty of steps with motion sequencing to boot that I’ve rarely used song mode.
The synth sounds are so-so, though not without their charms and doubly so when the valves are turned up to full (is there any other way to run them?), but the FX are actually rather useful, especially on external devices sequenced run back through the inputs – or even better gated by the EMX-1 – and then arpeggiated, for example. Lots of fun with noise boxes and monosynths.
The limitations of the synth engines, though there are plenty of them were, as I mentioned up-thread, why the Analog 4 appealed particularly to me as a next step.
Oh, and there’s a whole existing thread here about why it’s so good (and other opinions too of course):