I really like that you can now take a few levels as a Tome lock and still be an effective wizard. Heck, you can have 2 familiars through the spell and cantrip, and only be down 1 spell level if you take 3 tomelock levels. Also, the nerf to the higher spell slots isn't as bad if you go all in on Mystic Arcana as a single class warlock. It really gives the class a huge amount of flexibility. Sure the short rest nerf hurts, but it removes the tension of always pushing the party to short rest. I personally really like it. It still makes the warlock a terrific dip, but I don't think people will want to only take 1 level.
Cheers,
SG