I have a tendency to actually use my reasonably broad vocabulary in everyday speech, and I get the same thing from people when they hear an unfamiliar word: "Ooh, that's a long word."

No. It's not, it has seven letters (or other single digit letter count) and (usually) two syllables. Here "long" means unfamiliar.

I'd understand it if it was an actually long word and/or one borrowed from another language, like my current favourite, svarabhakti, but it never is. It's just an English word that happens to be outside the ususal 20-30,000 that the average English speaker has in their vocabulary.

On a side note, I've always tried to make sure that I pronounce non-English names correctly, and it's always stood me in good stead with the people I speak with.