The ES-9 price and size start to make better sense in a setup like mine, with Push as an interface for the software I can focus on instead of the mouse and pretty neat for mixing IMO, and also with willingness like mine to explore leveraging things like VCV or CV tools tu supplement the rack - perhaps I've made the mistake of suggesting better for me than for you :-D
If you're going to dedicate some space and money to an outboard mixer you don't already have, I think my advice should be to pickup up one of those mixers that has an integrated soundcard (some also offer in-built effects and what not, could be useful). Not sure about the midi connectivity though, and how important that is to you. If you really want Midi to CV as well, you have the option of getting that in the rack, picking a small sound card that can do that too, or a separate device just for that, I think there are some pretty small ones...
--- Voltage control all the things ---