I have my H40 packed away in my “just in case of EMP” box so I can’t directly compare. My memory says the H40 did wear a little lighter, but it also has a top strap (which may be overkill on a 1xAA light). Not to say the TH20 is heavy at all, though. I keep the TH20 as my go-to AA headlamp because it fits my 14500 li-ion cells if I wanted to use them.

For the most part I use my Wizard Pro these days and save the 1xAA for lightweight traveling.