I prefer different machines in different scenarios so it’s a difficult call for me.

MD is so musical & the most ‘instrument’ like. I love it’s architecture, it’s built for live jamming. It’s the only one of the 5 boxes that I feel I could take out live with no prep’d material whatsoever & still get a gig out of it.

MM is much misunderstood at first glance but is a treasure trove. The more time I spend with it the more I love it.

OT with very little prep can be like the MD in terms of musical flow. It also reminds me of the MM b’cos it can be a bit of a chameleon & change it personality depending on machine assignments/routing etc.

A4 & AR usher in better sequencers, better FX (generally but I still love the MM delays), & a lot more performance based features. That said they require more prep to get the most out of them IMO…
There’s a lack of immediacy for me that the MD had nailed & even the OT came close to.
An example would be ‘Scenes’. On the OT I’d never stop playback, you just dial in on the fly & away you go. I find this a bit fiddly on the newer boxes, the flow is lost for me.

Live…MD > OT > MM > AR > A4
Studio…MM > A4 > OT > MD > AR