I'd rate this movie between an 8 and a 9. Very entertaining and moves along well. Strong cast of people that would probably not be together except for an offbeat move like this. I LIKED the music in the background. Unobtrusive, but effective without trying to hype up excitement. I just happened to see it again today (3rd time) by accident. It's still as good as ever.
Over the years, I've seen a number of spy movies and this one is clearly among the more clever ones. The level of sophistication of the electronic tools used in the intelligence community was surprising then and made me wonder what kinds of things were really possible at the time.
If you're looking for blazing guns, car chases and repelling wires in watches, this isn't your movie. On the other hand, if you like your spy movies on the cerebral side, this one will do, quite nicely.