I had a couple of Eureka Mignon grinders, and I especially liked the Specialita with it’s timer function. Workflow was good when it worked well, not so great when it didn’t. I had to stick to full bags of beans at a time to reduce waste and the difficulty in dialling in with the EM dial.
I agree with the above somewhat, that retention of grinds from the previous day etc is unlikely to be detectable by mortals if compared with a fresh coffee after purging. Assuming timings, yield etc are similar.
However, my experience of the Specialita, was that the first coffee of the day could end up being very variable, extraction times wise, and in principal it could make a difference. Likely a combination of: stale retained grinds, coffee staling in the hopper etc.
Also, if I ground 10 shots, then on average you would get 18g. But the chute would often clog, and every few shots it would all get dumped out. So you’ve got several light shots and one heavy one. If you didn’t care to check the output the variability in the coffee extraction times did vary quite a lot.
It meant I would have to weigh my shots anyway post grinding, it just added more faff, with single dose on the duo, I weigh once and it’s done.
For home use I prefer single dosing, but can see how a large capacity hoppered grinder can be good for making back to back coffees. I have actually been on the lookout for a Mythos on eBay/scum tree, so I can give one a go.