I recently reinstalled Windows on my Intel X-25M with TRIM support. I didn't actually use HDDErase to completely clear my SSD because I read that TRIM will do the same thing. Whenever you format, or clear the recycle bin it will envoke the garbage collection and free up all the unused blocks.
Is this correct or should I perform a full erase using HDDErase to ensure I have optimal performance.
Yes is correct; you don't need HDDErase if you have TRIM.
Make sure it's working though, and run the Intel Toolbox utility.
TRIM only works on filesystems; NTFS. So if you have just one big partition that covers the whole SSD that would make sure it'll work correctly.
I personally prefer speed over capacity, and make a partition smaller than the full capacity. This is pretty much mandatory without TRIM. But it also increases speed a little bit as i've noticed with my cheaper 30GB SSDs; not sure about Intel though.