As it is only a 60 GB SSD (formerly in my 2009 MBP, which now has a 120 GB SSD), I store all my big files on a Firewire 800 JBOD enclosure with two 1.5 TB HDDs, I don't do much "big file copy processes" on the SSD.
But it is still fast to boot, fast opening applications and generally reacting more fluidly than with an internal HDD.
I left the sensor off, because I either forgot or didn't want. It is not, that the temp of the iMac ever goes beyond 60 to 70 ° C during CPU intensive tasks anyway.