usmle world has about 2000 questions. u can do 8 block per day as in real exam .it could be finished in 6 days for one time. then i suggest u start to use secrets/cover the answer , skip the question u already know and do only the one u don't know about. this can be finished in 3 days. then u can repeat the usmle qestions u get wrong in the first time.
but if u want to do only one i suggest usmle world. i just finished the exam on dec 7th, the exam questions has the same format. length and thinking process almost the same as in usmle world. i personally think no one should sit for step 2 ck, without sitting mle world.
