SPOILERS
It would be 5/10 for me, at best. Very messy, and uneven, as was the season overall in all honesty.
There was a missed opportunity to end the previous episode with an Infinity War-style downer with the dusting of cherished characters and to leave some real stakes in place. Instead, killing those characters off at the start of THIS episode was meaningless because you just knew it was all going to get reversed again (on the basis that the entire population of earth was extinguished).
I thought the best section of the episode was the brief moment in the future, finding the spoon, and the woman who couldn't quite remember what she had forgotten. That was nice, quiet, and resonant. The rest of it was just very hectic, noisy, and yes,
@Matteo, the music was a little overwhelming in places, and overused IMO.
As for the Ruby arc, I thought it was really poor, and a massive, Last Jedi-style red herring. To me it seems like they filmed the mysterious woman in the hood for the first episode without actually knowing how they were going to finish it. The notion that Ruby's mother was turning and pointing to a signpost, to indicate what she wanted her daughter to be called?!?!? Total nonsense. I wonder if there is a bigger behind-the-scenes story to this; that perhaps they changed their minds, cut some key episodes, or just didn't know what to do - but, to me, the whole notion of the memory being powerful, the snow appearing everywhere... That didn't get resolved.
All in all, as an episode, it didn't deliver. As a season, aside from Boom, and 73 yards, it was a disappointment. I would rank it above 13.2 & 13.3, and probably level with 13.1, and just below 12.3, which was the least effective season in the Moffatt era.
I think they need to go back to the drawing board a little here. I am fine with Ncuti Gatwa - he is evidently a very capable actor - but I think he needs to written more consistently and less emotionally outgoing. Certainly we need to see more of the 1000 year old alien in his mannerisms (which, for me, Peter Capaldi is still the high watermark for).