As you know, a long time Apple leaves a nasty habit of leaving to sign a version of iOS an hour after the launch of the new ago. Until then, if a user downloaded the new version and it was a serious flaw in the system, it had to wait for the apple company will launch a new version of iOS, which could take days. Now, after the release of iOS 9.3 and iOS 9.3.1, Apple has stopped signing iOS 9.2.1.
So far you could lose iOS 9.3.1 to iOS 9.3 or iOS 9.2.1, but is now only possible to downgrade to the previous version. From my point of view, and on the basis that Apple has to leave a available for download if needed stable version, I think this time you are wrong. I think they are wrong because the immediately previous version to the current saw how the bug that prevented access some links stretched, so, of having to choose one of the two, it seems that iOS 9.2.1 worked better on more devices iOS 9.3.
It is unknown how long will still signing iOS 9.3, so if you have thought downgrade, it is best you do it as soon as possible, as long as the previous version will work better than the current one. Typically continue signing up to launch a new version of iOS, iOS 9.3.2 can be 9.4 or iOS, but a new release in the short term is expected. With two months after the WWDC, developers will already be focusing on iOS 10.
What is certain is that most (or all) users seem to us better to install the version of iOS we wanted, but we know how Apple: the first is security, although that is reason for criticism.