I ran C300 on ARC1280 and LSI 9211. The LSI 9211 was CPU bottlenecked.. or so it seems because it would hit 25% usage and not go over (single core of the CPU).
Even though IOMeter should be multi-threaded, it doesn't mean the OS scheduler can be

On LSI 9211 I can get >200MB/s for both random reads and writes, which is more than what Anand and others got in their reviews by a noticeable margin.
I disagree you won't see benefits of large sequential speeds; I work with VMs a lot, and the extra speeds make C300 a lot faster than X25-E (X25-M is not even a player in this field!).

Now as far as TRIM into RAID goes, I disagree with the mentioned logic. The OS needs to know, at the least, the page size of the SSD and it would be optimal if the cluster was the same size (or a multiple of it). If the cluster size is smaller than the page size, you will see deletes that cannot send a TRIM command "correclty" - i.e. the last SSD page of the file would only need to be partially invalidated...
It's the same with RAID TRIM. Make the stripe a multiple (or equal) to the SSD stripe size. Make the cluster a multiple of the SSD page size.
There's no problem in sending a TRIM there.