Yes, it's the holidays, but I've gotten much more time than usual to study chess the last few days. As a result, I've now finished chapter 17 of Boost Your Chess 1, helped a lot by the fact that 15-17 were fairly easy chapters.
The plan is to finish this book, then take another break from Yusupov. My wife got me another Soltis book for Christmas, "100 Chess Master Trade Secrets", so I'll study that before moving on to the third Yusupov book. This Soltis book looks like one of the good ones (he has written some pretty useless stuff as well as some very good material). The "trade secrets" are 100 frequently recurring patterns and how they are handled: key priyomes, must-know endgame techniques, standard sacs, and exact endings.
https://www.qualitychess.co.uk/ebooks/Chess-Tactics-Scratch-excerpt.pdf
https://web.archive.org/web/20140708091717/http://www.chesscafe.com/text/review851.pdf
http://www.jeremysilman.com/shop/pc/Inner-Game-of-Chess-The-77p3897.htm