You know me - everything I do is derivative. In my apt format I added an income multiplier analysis to my sales comparison, which essentially obviates the need to try to make individual adjustments to the units of comparison. Other than that all my forms look like a cross between the UCIAR with some elements from my narratives and from the AI forms. My multi-family rents and sales comparisons grids (which don't have adjustment fields) resemble those from the 71b.
I think the two things I like most about using a single basic format are that my readers can follow the report from front to back with no switching around, and all the fundamentals are in the same order and with the same format regardless of the property type. I (normally) do one page for my neighborhood, one page for my site, one page for my improvements, one page for HBU and methodology summaries, etc. I do different improvements pages for SFRs and multifamily and commercial/industrial, and different grids, but the front and back ends are virtually the same across all the different versions. If a reader can read one they can read any of the others the same way.
I don't necessarily save any time using my own formats vs the conventional forms, but I think they're easier for the reader to read. I have plenty of room to write in complete paragraphs and I've lined up the gridded fields so they "line up" down the page and are tall/wide enough for easy reading. Generally similar to 1.5 spacing in word.