I've played a fair bit of Kings of War using timers - it really makes you speed up the bits of your game that are needlessly slow, such as getting dice ready, rolling and selecting dice to roll again, etc. It does always make you make decisions a bit quicker - but you still tend to spend a minute reviewing the game before committing to your go. KoW has the advantage of being entirely IGOUGO, the active player does everything in their turn, the passive one does nothing.
But I wouldn't want to play this way all the time - but having played this way it is good to have picked up some of the things that speed up all games. But you also have to be aware of how different people want to play - some want a much more relaxed game with time to chat and just let things bumble along.
I think for a game like WM, I wouldn't want to play with timed combat rounds, some combats can take a long time to resolve due to many rounds (WMR will help with this). But I would be happy to play timed for the command and movement phase. Horde armies may have more stands to move, but elite armies tend to get off more orders, and everyone gets to fail orders, do nothing and save time!!