Reading exercises

Hello,

I would like to hear your opinion on SAT reading tests. Are they suitable practice material for students who study English as a foreign language? Are they considered to be more demanding than CPE reading tests (Cambridge Certificate of proficiency in English)?

I have cast an eye on old SAT papers and they look interesting. They have sentence completion tasks which are useful for vocabulary revision and there are also questions on longer reading passages. I've learnt that the American students' average on them is below 50% so they must be difficult.