Scicree - I had the same exact thoughts and you were right on.
At 30 oscillations I had an average of 155 seconds. Prop weight is ~14 pounds as each individual blade weighs just a hair under 3.5 pounds.
Also installed it on the 700T. Wow, what a difference a blade makes in vibration. Slightest kick on startup, but normally expected and nothing like before. Pretty smooth idle at ~1600 to 1700 rpms once warmed up. Adjusted pitch for 5000 max rpm static which ended up being close to the nuetral range of the IFA adjustment. At max pitch I could bring the max rpms down to ~4000. Shut down is pretty calm. Overall, it's running like I had originally expected as far as vibration goes so I'm positive the prop was causing all of my issues.
Edit: Got the pitch adjustments wrong. Now fixed in report above.