Unless you play all of your golf hitting indoors off a mat into a net then you MUST be outside to get any legitimate comparison.  You must see ball flight , hit off of grass.... If you're going to spend several hundred dollars it is worth the time to compare them corrrectly and indoors at a store is not the correct way.

steve ball

Steve, you are so right. I have made the mistake before by getting fit after hitting balls indoors on a monitor. I made it a point to play on my course with my pro's input. Thanks for your response.

Perhaps you could slide in to a store with a launch monitor and get some number for us.  But based on what you have written, I probably wouldn't go with the Nippon for a "high swing speed / fast tempo" type of player.  I would suggest the s300, s400, perhaps the Project X 5.5 and at least 1 degree stronger lofts. 

See if you can find one of those combos and let us know!

Thank you both for you replies. I was able hit the demo 6 iron with s300 outdoors on the course. Hit it high with a slight fade. Might be attributed to lie angle as I usually am fit 2 degrees upright. Found a used set with S300, 1/2" longer, 2 degrees upright done by Titleist . Exactly what I was looking for.