V1R
I never found the Thoms books easy going and I am a ex RAF aircraft engineer they are too technical and while the idea is good they cover more detail than you really need for starting out.
The Pratt ones are definatly easier to read and give the same information that you need to pass the exams.
Why buy the Thoms when you may struggle and end up going for the pratts like I did after and spend more money?
I find now that I reading the Thoms after I got my licence to increase my knowledge in the areas I was not trained in while in the RAF.
I never got an oral on the plane did anyone else? I know I should have, Maybe thats just an examiner preference.
But good luck with the flying!