Re: Good #25 chain breaker?
 

At the beginning of the season we purchased a chain breaker very similar to the one you found on amazon. I was very disapointed as it broke after a couple of uses. We then switched to using a dremel to grind off the pins and it has worked very well.

Re: Good #25 chain breaker?
 

Here is a team created #25 chain break (our commercial one did not work well, bent the chain and was very difficult to use).
Picture one shows it in action. Picture two show a .1" hole about .75" deep in a 3/8"-16 bolt with lock nut inserted in a 1 1/8 long nut. The cut out in the nut is 3/8" long and 3/8" deep (cut on mill). Picture 3 shows the other 3/8" bolt with a .900" hole drilled about .5" deep with a piece of .900" HHS (like the back of a small drill bit) Loctite in place. We TIG welded a handle on and use this in a small vise. Takes about 20 minutes to create.

Works great and fully supports the chain.