Make my own notes -- seems like on my 870 the best setting using the spring action H/V foot is to set the tension at 3.6 to 3.8 and the pivot height at -2. Once you change the tool setting to either free motion setting, go to the top of the listing and you will see the tension has been automatically changed to 3.0 and the pivot to zero. Do test before use on a scrap quilt sandwich with the same batting...
You might want to visit or join one of the Yahoo Groups -- they are free. The H/V groups include the one for Sapphire, where you can ask, and think that you will find there is one for the Diamond. This is my second spring action foot -- the first one lasted about 4-5 years before the wire broke -- pretty sure in my case it was because of moving too fast! I use the floating foot more than the spring action...just personal preference.