I applied to US grad schools with a Canadian Masters (2 years) and a Canadian Bachelors (4-5 years). At schools I applied to, the amount of waived credits ranged from zero (i.e. nothing is recognized) to "no minor requirement", which was 3-4 courses. In Canada, a MSc is a pre-req for a BSc (I finished 4 (13 week) courses in my MSc, if I had stayed at the same school for PhD, I would only need 3 more years and 3 more courses). So I think our masters is like yours. But in terms of time, doing a MSc elsewhere usually means those years are not "counted" towards a PhD in the US.
However, I don't think the years are completely wasted. I definitely think I got into a better school than if I had applied directly from BSc. The extra two years gained me a lot more research experience and more importantly, time to publish my BSc thesis work! I also think I will be more prepared to tackle grad school life with 2 years of experience already. And when I was finishing my BSc, I wasn't 100% sure if I wanted to do grad school even, so committing 5-6 years in another country didn't seem like a good idea. 2 years MSc first gave me time to decide and be more focused now that I am starting a PhD.
I should note that although I went with a school that didn't give any credit for my MSc, the course requirement is 10-12 (10 week) courses. The other school that offered 3-4 courses off actually required something like 16 (12-week) courses! Anyways, it will be weird for me this year to take more than 1 course at a time in grad school -- I'm used to a system where research is the priority from day one!