Actually this is way off, where did you get this info? You actually only work 15 days out of 30 with the flex, one less than you work now. It's not that bad a schedule actually. You have the same 9 days off in a row out of every 30 (so every thirty days you'd have days 15-23 off for example and you can plot that 9 days around the sched). Out of the rest of the 21 days you work 15 of them and will never be on the road more than 8 or less than 4 and never be home less than three. So two examples of possible combos is 9 off, 8 on, 6 off, 7 on or say 4 on, 3 off, 5 on, 9 off, 6 on, 3 off. You can't choose your what days your 9 off will be, scheduling will do that but once you have those days assigned they won't change. Oh yeah, and if you do work 8 in a row they have to give you a minimum of 6 days off.
You don't have the exact same predictability of the 8 and 7 around the calendar, but the extra day off out of 30 gives you 12 more days off a year for the same pay. So it's not as bad as you seem to think. I think I'll personally stick to the 8 and 7 I have now because i have the big holidays off for the next two years, but I can see some people volunteering for this once they actually figure out how it works. It's spelled out on the pilots website, they just acutally have to check it out, which a lot of people haven't bothered to do yet.