The bunkers at Banff aren't bad, henrye. They're pretty rugged in fact, aren't they. I'm not sure they resemble Thompson's original creations though. Not sure, I haven't really studied any old photos of the course.
As far as Banff's "ranking" is concerned, everyone has their preference. It's the flattest of Thompson's "top 5", which might knock it a few steps down in my book. And I think the course has a few more indifferent holes than Jasper, St. George's, Highlands Links and Capilano. I could be wrong though.
If Westmount were in excellent architectural condition, I might even prefer it to Banff - scenery aside of course! Maybe not though...