Michael Sternbach
This is something that I struggle with in the RWS as well, and is why I lean towards TdM (because OP was asking about reading non-scenic pips earlier). I enjoy that the Thoth pips are more suggestive than anything else. It's as though the cards are saying "you can go in this direction... if you want to."
While the RWS seem more explicit (and sometimes deceivingly so), no Tarot cards are unambigious in their statements. Not only can each card mean a bunch of things, different readers also have a different understanding of a card as Zephyros' comment shows.
Therefore, I can get something useful out of most Tarot books, and that includes Arrien's book and the ones that followed in its wake (Tarantino, Ziegler, Wanless etc), even though many traditionalists turn up their nose at.
Likewise for the RWS, I don't limit myself to Waite's Pictorial Key (and I don't know anybody who would do this), but also take into account what Pollack, Banzhaf, Katz & Goodwin etc have written.
What it boils down to is that the true card meanings often defy the written word, as they have to do with feeling tones and psycho-spiritual states, and only experience will teach you what a card really means for you.