I found Pratt much more readable too – though the books are physically heavier (a consideration if you're thinking of reading them on the train!). And I think photos can often be more useful than line drawings. I found the Thom style comprehensive but old-fashioned.
The main criticism of the Pratt series is that the volume on technical stuff (book 5? could be 4) didn't go into enough detail to answer some of the exam questions. When I found I couldn't answer half the questions in the PPL Confuser I was lucky enough to find the Thom technical volume in a second-hand bookshop and used that - much more detail.