RTH has a few more features then bugzilla, but i feel bugzilla does a better job of handling "bugs" then RTH. That being said, if your looking for somthing better then bugzilla (IMHO) i would look towards Mantis. It can be run on a LAMP stack, so it is super simple to setup,run, and configure. There is a great community that has many customizations and modificatios to meet many needs.
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