Upgrade Crucial m4 SSD to 040H firmware?

Hello,
Several months ago, I installed a Crucial m4 128GB SSD into my black Macbook (3,1) 2.2GHz Core 2 Duo with 4GB RAM, running Snow Leopard 10.6.8 (NO TRIM enabled). This replaced the stock hard drive.
Back then, I read lots of forums that said for Mac people to not upgrade their firmware past 000F. So I have stayed at that firmware and experienced only minor issues. At first, their were slow downs and beach balls. But Crucial told me to leave my computer at the BIOS boot up screen overnight and that seemed to do the job (something about doing garbage collection when no other services were running).
Now I see there is a new firmware (040H) and wonder if I should upgrade. I have no problems with my current setup other than my fans working harder than usual every once in a while. But I wonder if the upgrade would offer any noticeable improvements to speed, performance, etc. I know I will never achieve the SATA III speeds with this old macbook, but I want the best I can get.
So I wonder what this community says: upgrade or stay put? Any experiences or insights?
Looking forward to your thoughts.
RJ

You never know what your missing

Though I agree with the "don't change what ain't broke idea in general, my question is more about what I am missing by NOT upgrading. Have people seen improved performance and speeds that I should take advantage of? Have the risks been addressed making the upgrade an easier decision and process for me? Any insights and actual experiences would be greatly appreciated.
RJ