Thanks for the info. These are all electronic ballasts. Did some pondering and thinking and really do suspect a bad batch of bulbs from Philips, or with the 700 series, the filaments are not as strong from the factory thus leading to easy failure. See below.
One of the 100+ that have burned out with less than 4000 hours. Some as few as 500 hours I am guessing:
Here is one of the 700 series in use in the fixture. Note the part of the filament that has fallen. This bulb will be going out within the next week I am sure.
Here are some 5-6 year old Philips TL730s that I removed from one building and am putting these in the building that the 700 series are burning out in as I want to keep the warm white color in the newer building where as we can go with the cool white colors in the older buildings, due to the wall and carpet colors.