Couple of things.
First, it's a great game, and very much worth every penny.
I would recommend it strongly to anyone who has any appreciation of RTS whatsoever -- although I'm not entirely sure what this might mean in your case, if you're really more of a 4x guy.
But it's a lot of fun, especially for collaborative play.
As to APM, I only partly agree with what the other folks have said.
My own experience is that the game's APM requirements tend to ramp-up as you play, and spike towards the end of each game.
For MOST of the game, the requirements are pretty modest.
But as the game drags on, especially in larger maps, you tend to have a lot going on, and your attention is necessary on a number of fronts simultaneously.
It can keep you pretty busy.
Not sure if it ever reaches cracked-out-hamster-on-wheel levels of busy... but there can definitely be some very stressful moments, and it is easy to forget about things that you SHOULD be handling. 
I think it is also worth noting that this is actually one of the things that makes Ashes really unique IMO.
There aren't many RTS games out there where matches can drag for an hour or longer...
If you're really evenly matched with an opponent, it can occasionally get close to a very epic two hours.
That's one heck of a win.
