@stonecliff, sorry for the delayed reply...ate too many chocolate bunnies on Sunday.
Your understanding of Flex versus Water as Needed schedules is correct. Flex schedules are delayed based, whereas Water as Needed schedules are skipped based.
Yes, potentially. We were hoping to explore this for the 2.5 release, but had to put it on hold. As Franz mentioned, we want to continually to improve our system's efficiency and app simplification. User feedback is needed do this. As such, we'd love to get feedback from Flex Schedule users on the new schedules...just make sure you only disable your Flex schedule and don't delete it if you choose to test out the new schedules.
@bzimmer, Water as Needed schedules use the same equations to calculate your watering duration by zone. We'll re-crunch this number on a monthly basis, but the duration won't change much much month to month (a few minutes +/-).
Water as Needed schedules will do their best to take advantage of what Mother Nature throws your lawn. We'll skip using a number of triggers (rain, ET & temperature), but you'll never go empty -- MAD (management allowed depletion) is running in the background to ensure you have the reserves to skip. We'll never allow the zone's moisture balance to fall below the permanent wilting point. It's really no different than waiting to fill up your half empty (or half full ) gas tank until the next exit in hopes of a lower price, or the following day when the weather is nicer. By default, MAD will always default to 50% and the related schedule interval is aligned to water accordingly. If MAD is changed on any zone, the interval will also change as the water requirement will be different.
In the comparisons ran during testing, the schedules balanced out pretty well. i.e. # of actual watering events over a given month on Flex schedules versus the number of watering events on Water as Needed schedules with skips removed.
Since Water as Needed schedules will not delay the schedule, but actually skip, the schedule is applying a managed stress principle to the zones, which will help encourage deeper root zone growth as anytime the moisture balance falls below MAD (i.e. 50%), the roots will search for water. Plants are very smart. If there's water, they will find it.
@cwagz, quite the opposite -- the magic will only get better! 2.5 schedules will be easier & smarter. I hope everyone will give them a test drive for a month or two and let us know what they think.