I do love time travel stories. This is an odd one, in that it doesn't seem to want to take itself too seriously. Of course, most time travel stories don't but this one in particular feels like it plunges ahead with abandon, not really caring too much about tidying things up.
It's good fun, though. I like that we revisit past events and there's a serious continuity nod by bringing back Captain Braxton (even if he's played by a completely different actor). The episode moves through different tones and ends in a very different place than it starts. Jeri Ryan is given a lot to do and - as usual - pulls it off very well. Once Janeway becomes involved in the time travel shenanigans it really begins to become great.
The ending is a let down, in that everything is wrapped up quickly and we're told not to worry, the timeline will now sort itself out and things were done off-screen to fix all the causality/paradox problems. And all the different versions of people will magically recombine into one. Somehow.
Slight continuity issue that really jumped out at me: the Doctor is activated for the first time at a completely different moment to what we've seen/been told before (everything previously has stated he was first activated in 'Caretaker' once they were stranded in the Delta Quadrant). What we see here does make more sense, of course, as you would think he would have been turned on previously for testing purposes if nothing else.