So far, I have skipped the buying of Magi of Hermes and Tales of Mythic Europe, since they are a kind of book I generally find limited usefulness for. However, a recent side remark in a thread made me curious: have new crunchy bits (such as new Virtues/Flaws or spells) been published in those books, and, if so, what is their general nature ?
Yes. Cool stuff 
Well, the crunchy bits in ToME and MoH are the ideas rather than any new set of virtues or flaws. ToME presents a set of interesting and refreshing scenarios that really inform storyguides on how many of the previous supplements can be leveraged. They provide, I hope, a demonstration of how each realm can pose a real challenge to a covenant and how Hermetic and mundane politics can be as difficult and threatening as any combat. If spells and devices is what you're after then MoH is the book you need. We'll see when it's published but this is a resource that will be useful to every player.
Vested interest alert! I'd recommend both, but based on what you're looking for hopefully the above will help you choose. Personally, they're both books that I would buy for different reasons.
I initially purchased ToME for sake of completeness and have been really surprised by that book.
It contains some crunchy bits (like low level spells that explain how to train some skills during apprenticeship really nicely) but mostly contains refreshing adventures which can be used almost in any campaigns for most in not all of them.
I definitively recommend it to any game master that want nice adventures with a medieval theme to them.
François
I also REALLY appreciated how, in some adventures, they tried to find way to introduce them to the players through their flaws and/or covenant hook. While very simple, this is, IMO, an invaluable lesson to every GM.