I did have a few leaks, but that's because the bulkhead is just at the part of the pot that starts bending in towards the bottom and the o-ring kept creeping down. Readjusted and reset and no leaks! Ran it through a boil test to calibrate the Thru-Mometer. Since we are at elevation 1,850' MSL and water boils at roughly 108.5 degrees (f).We got to a boil and reached just under 108 degrees (f). So I think it is spot on. I compared the Thru-Mometer readings against my glass thermometer at different temperatures, and the glass thermometer was always a degree or two higher, so that's pretty close. But the glass thermometer went up to 120 degrees (f)
once at boil. For anyone who is interested, I put a step by step on my blog site. As far as loss at the bottom of the pot, I've been thinking about that, but more in the context of a installing a sight glass, so I can account for the loss in the site glass.
Brewhardware.com has a "Weld-less Flex Sight glass" that uses high temp silicone tubing rather than glass for less than 30 bucks. Due to the fact that my HLT is only 5.5 gallons and only about 12" in height, the flex sight glass looks like it'll work out as I can cut it to length.
Note: The BrewMometer crept up in temperature smoothly except when we got to around 180 degrees (f). From that point on, a little tap on the glass was required every once in a while to bump the needle. But that's at a temperature above where I will be for an HLT, so it's okay... for now.