I got this bad feeling about how I insert larger amounts of HTML. Lets assume we got:
var html=\"
..
\"
For starters, write a script that times how long it takes to do it 100 or 1,000 times with each method.
To make sure the repeats aren't somehow optimized away--I'm no expert on JavaScript engines--vary the html you're inserting every time, say by putting '0001' then '0002' then '0003' in a certain cell of the table.