A snarky description would be travis-ci is to jenkins what github is to sourceforge.
Travis-ci definitely has limitations (no windows support, limitation to 15 mins for build time, very difficult to have it installed on a local network), but if it can do what you need it to, it is the best solution I have seen.
We are in the process of adding Windows support, we don't have an ETA just yet, but it is definitely in our sights! Also, the build timeout is 50mins, with a 10 min no-logs timeout.
Travis is great. My only problem is that I have sometimes agonized for days or even weeks over undocumented changes and features for travis.yml resulting in "broken" builds, and had to figure it out myself.
Still love it to death, especially for verifying pull requests and branch merges.
Travis-ci definitely has limitations (no windows support, limitation to 15 mins for build time, very difficult to have it installed on a local network), but if it can do what you need it to, it is the best solution I have seen.