> I find that creating usable sounds is much faster with analog

This is a huge part of it for me too. It's so much faster to make a noise that 'sounds right', sits in a mix without excessive EQing (or sometimes any EQing), and requires very little support from additional effects units and has a natural modulation. The fact that you have to let a lot of synths 'warm up' first kinda indicates the magic that holds them together.

This also translates to the mixing, I use an analogue mixer too, and the summing of the channels 'just works'. Everything sits in the mix better and I spend less time making it work like I used to in-the-box.

That removal of technical hurdles helps keep the creative juices flowing, where previously I'd walk away from a track in frustration because I couldn't 'quite get it right'.