The thermal-resistant coatings will help the life of your pistons, and likely with prevention of pre-ignition and detonation.
The low-friction coatings will help with your power output, as less friction means more combustion power gets to the flywheel, as well as resulting in less heat. Probably would help the life of the bearings too.
IMO, if you've got the engine apart to replace something (i.e. burned piston, busted ring lands, spun bearing) it might not hurt to have some of it done. But it is probably more like doing a major interior gut or some other drastic measure, more like one of the last things you do to squeeze out every last bit of performance.