I've seen a few videos of Blauer's SPEAR system at CrossFit.com and found them fairly interesting. He's not trying to teach some self defense style: his entire program is based upon the "flinch" response, what the human body naturally does when it feels itself threatened.
Very interesting, and indeed many parallells to aikido.
There are many martial arts that teach ways of polishing one's reflexes, so that they become efficient first responses when attacked.
If you don't evade too much from instinctual "flinches", you can alter them slightly, so that they become very effective although still as quick - or even quicker after persistent training of them.
I tell my students to start with responses that are likely as quick reflexes, and could be done also when you're surprised. There are some such movements - not that many, but more than the flinch showed in the Spear videos.
What is important is also to practice the taisabaki evasive turn of the body in connection to the arm movements. It can also become a reflex, and it improves the whole thing tremendously.