Increase in shutdown time after enabling TRIM

Question

Hi,
I'm using mid 2012 macbook pro 13" & recently replaced the original hard drive with Corsair Neutron GTX 120GB. After replacing the HDD I freshly installed Mountain Lion. The performance benefits were conspicuous just as any one would expect. Faster boot/shutdown times (~12s/~4s), no jumping apps etc.
TRIM support for SSD was not enabled until I used this app called Trim Enabler (http://www.groths.org/trim-enabler/). A subsequent reboot enabled TRIM (as you can see below).
The weird thing I observed after using Trim Enabler is, shutdown now takes around 20+ seconds. I'm not sure if this due to some clearing activity through TRIM commands issued by OS X (considering TRIM was not active initially) or anything else.
NOTE: I don't see any visible performance impact other than the higher shutdown times.

Answer 1

I'm not sure what actually caused the slower shutdowns, but now ther's no issue at all
Possibility 1:
The local copies made by Time Machine to SSD (when backup disk is disconnected)
Possibility 2:
Considering there were few writes to my SSD earlier without TRIM, after enabling TRIM OSX took some time to get the SSD to optimal performance (may be few background copy/erase operations, I don't know for sure)
Now that I've switched to manual time machine backup (turning it ON only when the backup disk connected & turn OFF once done) the reboot time is back to blazing 2-3 seconds.
BTW those who still want to keep backup running automatically & don't want to keep local snapshots on SSD, should disable it using "$sudo tmutil disablelocal" (there's no GUI way of doing this). With SSD there's a good reason to disable local snaps by Time Machine; space, life, performance etc.