The deals are live now. My feelings for Q-Squared and Imzadi are more mixed now than when I was a teen, but they both still have enough amazing moments to be worth $1. McCormack's books seem to be getting better as I get older, so I also picked up TNES for a reread.
I could say the same re: my feelings on Peter David's Trek writing in general. I loved his stuff as a younger reader - Vendetta was either my favorite or second-favorite Trek novel, depending on how I was feeling about DRG III's Twilight at the time, and Q-Squared was top-5. I loved Imzadi, thought Q-in-Law was sidesplitting, and devoured every New Frontier book as soon as it hit shelves. I don't know whether it's a matter of some aspects of his writing not aging well, my tastes just changing as I age, or some combination of the two, but I haven't found a book of his that I've liked more on a re-read than I did back then.
(I still picked up Q-Squared and Q-in-Law. Heh.)
And Una McCormack is the bee's knees. I don't think she's written a Trek novel that's worse than "very good," and The Crimson Shadow and The Never Ending Sacrifice are all-timers. Even "more minor" works like The Missing are delightful.