I ride everything in my little nubby spurs. Also, when I started riding again after a long "hiatus" I found that having the little spur on made me hyper-aware of my leg and thereby forced me to focus on strengthening my leg in the correct position, like NOW. But that's just my personal experience and opinion. Woo!
Americans are just Canadians that someone fed after midnight.
Most of the time, and especially if I'm on a horse that only needs the reminder of the spur occationally, I position my spurs all the way down on by boot rather then on the spurrest. That way the spur will not ( as long as you hve a somewhat normal lowerleg position) touch him as long as I'm just riding around and I will still be able to support him with my lower leg without the spur touching.
If I do need to get him to pay a little extra attention to the leg I will just lift my heel a touch and let him feel the spur for a step or two.
And then when I go in the ring and need him to react quickly I push the spurs up a bit and get a nice reaction even from a short soft spur as he's not used to it poking him all the time.
My experiences with motivator spurs is that they are used much more involuntarily than regular spurs because they reach so far to the inside. I actually prefer the roller spurs for riders that need to learn to pull their toes in or generally spur-novice riders. The rollers are really soft on the horses side and as a rider, you really feel when you are using them.
I also liked the point about putting spurs on below the spur rest. Waaay back when I was a younger rider and getting used to spurs I used to sent them closer towards the heel and I felt it helped me get more comfortable with them. You can't do it for too long though as it will create a habit of bringing the heel up when applying leg.
I ride in spurs on most of my horses (90% of which are OTTBs) and have learned over the years that the sensitive, fast horses are the ones that need spurs the most in order to encourage them to learn that the leg does not always mean GO. Sometimes in means move your haunches over, or step sideways, ect.