I don't know of any online examples, sorry. The problem is that a well-aligned festival voice is not academically interesting, so people generally don't publish it. Festival performs well when it can rely solely on unit selection and has multiple choices of the same phoneme sequence. Once it has to do some guessing on the synthesis, you'll see a drop in quality.

With a small bit of work, you can have festival use an HTS voice directly. I usually use festival to generate my label files, post filter the phoneme timing, synthesize with HTS, then apply a post-filter.