I've had plenty experience with running into spies on my side of the map and quite honestly, I find that they hardly stay spy for very long (the ones that cross the bridge). Also keep in mind that the entire time they are cloaked and sneakily moving about is simply time they cant do jack shit except giggle as you appear completely unaware of the fact that they might de-cloak behind you only to alert you on their first shot. I actually find it fun playing against spies at distances as well as close up because it throws me off. It's good practice for those same moments you are likely to end up having in Highlander when wearing your Razorback. There is also good practice in getting headshots on spies that cloak 2 seconds beforehand. Improves leading on hard to see targets tremendously.
Team Fortress 2
Counter-Strike Source
Counter-Strike 2