Nah, the new rev LS is lower wattage now.
The temps are pretty similar, the mach's compressor is more powerful, and upgrading it later is an option.
The GT is using 404a gas, and getting the same or marginally better temps than the LS which uses 507 which is a better gas.
The GT is the better unit, really.
If you upgrade the gas at a later date, you'll well outperform the LS. The LS is already as good as it can be.
I think they're both at 210w heatload now, so no probs really with any core I know of.
Gray