I think the energy burn to make dry ice for a day's use isn't worth it, let alone the cost of equipment. I can go to the nearest grocery and get dry ice for $1.50/lb. There is also an industrial outlet 30 miles away by toll road - price $1.00 per pound plus round trip tolls and fuel. The carefully figured breakeven point between those two is 30 pounds. A VGA plus a 7980XE can easily take 60lbs in two days of benching. I'll go to the nearby store for 15-20lbs to do the iGP and memory frequency contest stages with a 9700K today.
I think the 9900K and 9700K I got from Silicon Lottery are winners within their top bin. That is, it's the CPU running like a beast and would on either mobo. I get frustrated with memory tuning and miss the ASUS BIOS in that area. So many users are doing better with low-latency memory profiles on M11 Gene and Apex. Maybe that's a case of the grass always looking greener... The mobo is in question because CPU socket pins keep getting bent just a little out of line. I fix them, but you know how well that works. One of the DRAM sockets might also be borked because it works so much worse than the other one. I'm trying to decide on a M11A vs another one of these that is sold in North America to replace this one if it goes out -- nothing ordered yet.
I know how that works frying CPUs, but I'm harder on motherboards. My first dry ice experience toasted a very good 6700K and the M8E it was sitting on--the CPU failed to a short circuit and the magic smoke got out of some VRMs. Since then, I've lost a M9A, two M10A and an R6A. Those were all strange intermittent performance drops that I suspect were socket solder joints cracking open because of thermal shock. I'm using a heater under the socket now -- Kingpin inferno -- but that didn't help one M10A and the R6A. R6As were unavailable by then, so my current X299 board is also non-ROG.
Why is condensation less of a problem with LN2? I see just as much frost on LN2 pots and I get with dry ice. To me, cold bugs, overvolting risks and alternating LN2 cooling with torch heat seem so much more complicated.