Glad you like it. Unfortunatly SpeedFan has no settings (at least the current version) to change the refreshrate.
Currently the value's are retrieved by System Monitor every 5 seconds, making it retrieve the value's more often wouldn't make a difference as the value's aren't updated faster by System Monitor.
But if you do want to try:
Changing the value of 5000 to a lower number on line 91 setTimeout('GetValues()',5000); in scripts/sysmon.js would make the plug-in retrieve the value's faster.
Cheers,
Danee