We've put up with the temporary shades the past year as a way to really see what we would or wouldn't want to have automated (or clearly not at all).
Are you talking 50/50 as to the number of windows being automated, or how often the blinds would be changed?
I don't think there's any numeric ratio of windows that makes or breaks the idea. For me it's one of marital harmony, automating some of the windows will keep us both happy. Having automation in places where we'd differ on our motivations for having the blinds open or closed will go a LONG way toward avoiding irritation. I can set schedules to open/close them as my wife likes, and go back to where I like otherwise.
For us, going with bottom-up shades will make for better solutions in places where we want more light but also need privacy. The master bath being the prime example. Over the past year we've had the temp shades up just high enough for privacy, while allowing full exposure through the upper portion. As a result it's clear that manual bottom-up 'cordless' shades will suffice. One the rare occasions that we'd want full exposure or coverage it'd be a simple matter to just move them manually with the on-shade handle (no ropes). This avoids spending for motors on five windows. Same thing with other places like a hallway, laundry and exercise rooms. Bearing in mind that we're on a suburban lot, so there's no 'view' we have any need to make more visible. Were we situated somewhere with much more interesting views then, yeah, we'd definitely be thinking about automating more, in order to keep those views visible.
I'd like to think this addresses the should we or shouldn't we automate question (perhaps also your 50:50 ratio). The bottom-up style allows for gaining light-passing privacy without losing being able to see daylight. We'll also be using the same kind of bottom-up shades, but in an automated setup for our living and adjacent dining room. Here we've got a lot of windows, and we'd like to keep the option of seeing the daylight sky. Most weekdays we'll have them automated for half-way up, and then fully open on the weekends. This is seven separate sashes, so it'll be spendy. But worth it for the convenience and, honestly, a bit of a guest 'wow factor'.
While I'm certainly capable of DIY, I'm definitely having these installed. If only because it was among my childhood chores to re-do all the window treatments as the seasons changed. What fun, switching from traverse rod drapes to sheers, and re-tightening or replacing the old spring-wound roller shades. It'll be a cold day in Hell for me to go through that again willingly... There are definitely a lot of little tricks involved with properly hanging it all.... once. I'll be glad to trade my money for being able to badger someone else to get it right.
That and noise isn't a huge factor for anywhere other than the bedrooms. And we'll likely only be automating the ones in the master suite anyway. Kids & guest rooms won't get it because of the abuse/damage potential. I suppose it does raise the question of just how quiet they'd "have to be" in order to avoid sleep issues. But I don't really foresee much in the way of problems unless they grind like a coffee mill. I'd likely fine tune their scheduling to avoid motion while anyone's nearby anyway, further reducing an big concerns about noise.