I know we love to bash on HF ballasts, but it's good to know that they actually take good care of lamps. There was an experimented conducted almost 17 years ago to testing the damage on lamps with each start. 

They setup up several sets of each T8 ballasts. Magnetic rapid start, instant start, Motorola style rapid start and one that appears to be a programmed start. They setup a test in the lab to repeat 5 min on, 5 min off cycles and ran the test on three different brands of lamps. I believe those three are Sylvania, GE and Philips, but they don't say.

In 5 min run, 5 min off cycles
They found that good old magnetic rapid start ballasts shredded half the lamps in about 3,000 cycles. Motorola type electronic rapid start killed them in 12-16,000 starts, instant start (in American definition, this is starting the lamp like neon signs using two wires)14-19,000 starts and what I believe is a programmed start got on the average, 43,000 starts out of lamps.

It's no brainer that heating them to just the right temperature THEN applying the arc voltage is the easiest on the lamps.
http://www.lighting-gallery.net/gallery/displayimage.php?album=1962&pos=0&pid=102338

Interesting stuff. What makes no sense to me, though, is that IS outperformed ERS, unless it just happened to be a difference in the lamp brands used. Other than that, though, this is quite eye-opening - I never thought ERS outperformed MRS so much, let alone at all. I'm not surprised, though, seeing as we're talking Motorola ballasts.  I would guess an ERS ballast today wouldn't perform nearly as well, seeing as it's basically IS with cathode heating strapped on.