Spock did not think in such absolute terms as "greatest thing ever" but if he did, this would most certainly not be a contender for that title.

That Jim apparently was intrigued in a positive fashion.... Spock suspected his research into how to fix this problem would be interrupted by Jim's own research into what possessing a female body entailed.

If it would not have been an entirely unVulcan action, he would have rolled his own eyes.