The bottom line is that without TRIM enabled the performance of an SSD will suffer over time. There is some great information on it on Wikipedia’s TRIM entry. TRIM is effectively a garbage collection model for SSDs. Derek brought up the issue in the comments and I spent some time investigating it. Hat tip to Eytan for pointing this out to me. At 820MB/s it is over 5 times faster than the SSD I just installed. Though quite a bit more expensive than a standard SSD, if you want the absolute best performance for a Mac Pro you may want to consider it.
There were two important things I found out after I started reading the comments from that entry: As I wrote last week, the SSD upgrade for my Mac Pro went very smoothly.