When you're trying to convince management of something, give advantages AND disadvantages. Try to stay objective, and give figures where possible. This will help you convince management (and indeed yourself). It gives management (and your team) confidence if they know you've actually thought something through.
For instance, I worked at a place, and we were looking at improving the speed of the ANT build. It was 8 minutes. I changed it a bit, and it was 3 minutes afterwards. Was it worth it?
We had 8 developers. Lets say they do 3 builds a day.
That is 8 developers * 3 builds per day * 200 days a year = 24000 minutes = about 50 man days.
That is, for a team of 8, if you save them 15 minutes a day, you'll get an extra two man months work from the team each year.
This not only helps you convince people/managers of the worth of what you're doing, but also helps you convince yourself.
P.S. About 6 months previously, we didn't have ANT, and the build was a series of 12 .bat files which had to be run in order. It tooks about 2 hours to correctly build. THAT change was easier to sell to the management.