In my view, this is the best SSY episode since the one in which Shun died. This episode and that one are also the two best SSY episodes overall, imo. There's just something about Saki losing a precious friend that so effectively tugs at the heartstrings, and makes this tragic tale so much more emotionally engaging and viscerally moving.
But I can't help but lament the timing of the lovely new OP and all of those absolutely beautiful flashback scenes of Saki's relationship with Maria when they were both little kids. I lament it because of SSY's unfortunate sales, and how this is the exact sort of material that I think could have helped literally sell SSY. But I fear that, commercially speaking, it may now be too late.
At a creative level, though, now is the best time for it, just as Saki and Maria are forced to part. Maria's letter was far more eloquent than Maria herself gave it credit for, and Saki's response to it was so emotionally rich and moving.
Saki's dream was pretty creative and well-depicted here, although I must confess that for this dream scene alone, I kinda wish SHAFT was animating this.
In any event, superb episode. The perfect episode to end off this section of the story on, before we make another time-skip.