I love "Regeneration". It's a lot of fun to watch. Those who can't enjoy it because it messes with their notions of continuity are watching Trek wrong.
I don't really my the continuity problems from 'Regeneration'. Mostly because I consider the ENT timeline to be an AU created from the effects of FC. Time travel was used to rewrite established history. Similar to what we see in ST09 with Nero and Spock.
I like that theory. That way neither ENT or NuTrek have any impact on proper Trek
Except canon explicitly states that is not the case.
From VOY: "Relativity"...
DUCANE: Let's see how much you've assimilated. The Dali paradox.
SEVEN: Also known as the Melting Clock Effect. It refers to a temporal fissure which slows the passage of time to a gradual halt.
DUCANE: The Pogo Paradox.
SEVEN: A causality loop in which interference to prevent an event actually triggers the same event.
DUCANE: Excellent. Can you give me an example?
SEVEN: The Borg once travelled back in time to stop Zefram Cochrane from breaking the warp barrier. They succeeded, but that in turn led the Starship Enterprise to intervene. They assisted Cochrane with the flight the Borg was trying to prevent. Causal loop complete.
DUCANE: So, in a way, the Federation owes its existence to the Borg.
SEVEN: You're welcome.