Thanks Luis.   As it turns out, it had to be either the server, or my copy of SSMS.   One or the other was mucked up.   I later ended up crashing SSMS, and it's been working fine in about a quarter of a second (EDIT: for 1,000 executions) ever since.   I tried using Jeff's DelimitedSplit8K at first, but the performance just wasn't there, and probably because I used the same split twice after splitting once to begin with.   I hate testing on shared servers when performance testing is involved.   You never know what you're up against...

 I ended up just using that original boiled down XML shred going into a temp table.  Turns out the doc prep execs cost an extra 0.175 seconds on 1,000 executions, so I'll have to not use that on this occasion.   Thanks again for creating a sounding board.