Thanks, Pete and Andy, for your replies.
I was hoping there'd be a straightforward way (i.e. without using a plug-in) to extract what I'm after via FSUIPC, but appreciate that its need to be very flexible and comprehensive in order to be very informative means that a particular combination of information (such as vertical speed on touchdown) needs custom-written extraction.
Recording vertical speed on touchdown is all that I'm after, so FS Flight Keeper feels like buying the proverbial sledgehammer to crack a very small nut -- certainly when compared with all the sophistication it seems to offer.
I'm surprised that FSX's own Flight Analysis feature doesn't include vertical speed on touchdown -- at least, I hope I haven't missed it.
Sincerely,
David