As strong as Amsteel is, it has properties that might not make it ideal for a bridge. With the small diameter technical ropes on the market now there is very little to be gained by using Amsteel. There are both sides of the argument spelled out in this thread.
People please do your due diligence and understand what manufacturers designed their products for and recommend for and against. There is like a encyclopedia put out by Samson on what you should and shouldnt due with Amsteel...including specific specs such as bend radius'. I edited this from...
saddlehunter.com
It basically boils down to using what you are comfortable with, just make sure you are informed when making your decision. I personally don't have Amsteel anywhere in my system.