Any game has a certain amount of downtime while your opponent does stuff. Sometimes that can be a few seconds, sometimes it might be longer. There are a couple of things your opponent can do during your turn in KoW, but not much. So it's really just a spectator thing. But it seems like the turns are much quicker than WHFB so while there's less going on in your opponents turn, there's probably less actual waiting over all.
One of the things I actually quite like about KoW is that flavour comes from the models and the players imagination, not special rules. I've long been a proponent of that style of wargaming where the individual rules don't actually matter, and if you want to run unit X, then you don't actually need rules to do that, you can just put unit X on the table and call it a day. IMO, this only falls down if the rules are either so generic as to be totally boring (and I don't think that is the case here, there is a fair range of diversity and different abilities in each list) or where unit X is so unique that it has no suitable analogue (in terms of rules) to represent it.
For instance, I will be using my Hexwraith cavalry from WHFB, as Wraith infantry in KoW. Because both units move at the same speed, have similar rules, a similar footprint (or they will with some careful re-basing), etc. So despite the fact that there is no ethereal cavalry in KoW, I can still use my Hexies.
Similarly, my Mortis Engine becomes a Revenant King on an Undead Wyrm with wings. Because of the single profile, I can strip away the 'revenant king' title and all I have is a model that flies, is decent in combat, and provides support for nearby undead units. That sounds a lot like a Mortis Engine to me!