The next release (beta 1) will force a wipe of all your profiles. Sorry for any inconvenience this causes, but I want to be sure that any reported bugs are actually caused by present and existing issues as opposed to alpha to alpha upgrades.
And in addition, features lost in 4.x to 5.0:
Global auras: I'm looking into a way to reimplement these, but it won't be until a future release. A possible replacement might be an automatic profile loading mechanism.
Secondary animations: I've got no interest in supporting these whatsoever, and I don't fancy re-implementing them either.
Tracking, AoE, Stealable/PurgeableSpell, Items/Slots and UnitMatch triggers: Various reasons. Items/Slots should be replaced by the Equipment trigger, but won't upgrade to that automatically. Stealable/PurgeableSpell are functions of UnitAura. Tracking, AoE and UnitMatch I've never seen used.
Ability to use a spell name/ID for a custom texture: One of those things that I'll fix eventually, I've just not gotten around to it.
Orbit animation: No interest in reimplementing it.
There's a per-profile limit of auras, it's set to 255 currently. I could double this, but I'm keeping the upper numbers reserved for now (I might be using them for global auras).
That's not to say all of those are permanently gone, they're just not present for now.