Nuts and Bolts
So far I haven't switched to the new template system, which is supposedly the best part, although I did try it on a test blog. Essentially all the customization I've done to the original template breaks at that point.
One aspect of this site, largely invisible, is that I have gone to quite a bit of trouble to make it compliant with standards for web pages (specifically, "XHTML 1.0 Transitional"). Although Google as a search engine supposedly much prefers compliant sites, the unmodified Blogger templates were riddled with non-compliant code. Go figure.
Just changing my account from Old Blogger to New Blogger, the main page went from zero validation errors to 21. The shift to the new template code will mean hundreds of errors even before any of my customizations are restored. I'm no expert at this, so this could take awhile. The best way to do it would be to regain compliance before adding the customizations back in. However, I don't want to wait to get them back, and just redoing them all will already be time-consuming.
So at some point in the near future DLMSY may get a new, not necessarily improved, look that will continue to evolve.