I agree with Rowuk, it takes quite a bit of time to really know a horn. Even longer when you begin making modifications to the horn that are after-market.
I've tried heavy caps on some horns, rounded slides, all the gimmicks, and I just didn't like them. On some horns, it deadened the tone, on others it changed the overall feel of the horn.
If you really spend a lot of time with the horn, you should get to know it very very well. If something is mechanically wrong, you'll know.
As far as the Amado goes, try a bit of valve oil on the end, and work it back and forth a bit. This will lube up the mechanism, and ensure that the sprring keeps it sealing up every time you depress it. I had an issue with the Amado on the 3rd valve slide of my C, it was way to stiff, a drop of oil solved that problem completely