I went back to a stretch/flexible template because so many embeddable objects are larger than the fixed templates can show well. And, of course, because I’m hooked on change!
If you are still creating web pages, you need to decide on fixed vs. flexible, not only for embedding objects, but for considerations of your visitors’ screen sizes. I’ve got a giant widescreen, and some fixed pages look silly, but you decide.
(And then I discovered that I had made both of my blogs grey. What’s with that?)