That was a good episode...it came close to great, but it was held back by some really odd choices.
It is nice to have some genuine forward movement in the plot. A lot of the questions of the season were answered here, more or less, such as what actually causes the Confederation timeline to come into being, and what the hell is going on with Q. I'm not sure how an entity which was formerly immortal can die at a set time when they can travel through time at will, but I will just presume that the Q Continuum has its own flow of time he normally "lives" in. Alison Pill is incredible now that she's in Borg Queen mode. I have to say I haven't seen her in much else, and playing two distinct characters (the second of which already had an established portrayal) showcases her range. I don't get why the Borg Queen also wants to interrupt Renee Picard's voyage though - seems like assimilation.
Amazingly, almost all of the characters are used well here. They remember that Seven used to be Borg, and it has plot relevance. Raffi actually gets decent use, and a flashback scene with Elnor where he is finally more than an extra (though his skill is still obviously limited). Isa Briones gets her best scenes of the season as Kore (the technobabble gives away she's a clone...but of who?). Picard gets a great inspiring Picard moment with Welles. Rios remains cute with his adoptive family, Spiner is great in his role as always. The only ones which seem a bit off to me here are Guinan and Q, who get good roles, but were better executed elsewhere.
The downside of this episode is mostly the scripting. There's some real groan-worthy lines, and even more which are...um...writerly, to put it nicely. They might work on the stage, but in a hyper-realistic fast-paced kind of modern production, they really pull me out of the experience. The attempt at cute romantic dialogue between Rios and Teresa for example - her hypothetical scenario about their being married for 10 years is just too detailed/drawn out to realistically be something that a character would come up with off the top of their head. There's little bits of that between Soong and Kore, Q and Guinan, Seven and Raffi - overwritten long-winded monologues which are just too "perfect" to be said by real people. I also thought Guinan's appearance during the brown-out when Picard was being interrogated was laughably awful - unneeded to move the plot along, and seemingly establishing an additional power that El-Aurians never had before.
Still, on the whole, it was a good outing.