Just because SysMain (former SuperFetch) uses up a little bit of your CPU resources and a lot of your memory, doesn't also mean that it steals the resources from your other processes like playing videogames. Read up on the concept of InvisiTasking, which allows background processes to use up only those system resources that would otherwise be left unused, so for example if you have Condusiv Diskeeper service running in the background, then it can optimize performance of your HDD (it works for SSDs too, but on a modern SSD the performance gain will typically be negligible) and 1/ you never need to defrag because it prevents HDD fragmentation before it happens, while 2/ it greatly reduces the total number of I/O operations on the HDD in addition to keeping enough free space near the outermost cylinders of the HDD which is where the write speed is higher in comparison to the innermost ones─yet another reason why dividing your HDD into separate partitions never was among bright ideas. SysMain touches on the same principle that preventing I/O at the only sacrifice of using the specific part of CPU and RAM that would otherwise just sit there, doing nothing besides costing a lot of money of course. You see, other processes don't have to wait until these background processes release the system resources that they use. There's no delay there, the other processes take immediate priority.
That being said, with a modern Intel CPU, although this greatly depends on system design, you could say that temperatures should also be seen as system resources. That's just because technologies like Turbo Boost and Speed Shift can be used to increase performance, only temporarily when needed, and in such a way that the heat energy resulting from this temporary increase in power (far above the TDP) has to be throttled back down again after a certain period of time in order not to exceed temperature constraints. These constraints are configurable and can be set by the system manufacturer. Some of the settings are accessible via the powercfg command, some aren't. But that is why I use ThrottleStop. Anyway, my point is that disabling the SysMain service isn't going to have any noticeable impact on temperatures, any more so than homeopathy is. So I'm not too worried.
