I've skimmed through this topic so forgive if I repeat anything here that has been mentioned already.
The iSSD, as I understand it, doesn't actually speed up your HD; it only speeds up access to frequently used data. That is to say, if you're using a program that frequently would read the same block of information off the HD this is recognised and the data is then moved to the iSSD cache so that it can be accessed more quickly. For this reason testing programs that measure data throughput need to be run a few times to get meaningful results because, initially, the data being used for the test isn't in the cache.
I recently did a new build using the iSSD board, followed the instructions in the Smart Reponse installation guide and everything went perfectly (to my amazement ) Having said that, I haven't a clue as to how to see what the improvement is in real life applications (as against testing programs)