I just took Kaplan for my LPN to RN bridge program and used it to study from for NCLEX-RN. Before using Kaplan I would have agreed that NCLEX-PN was alot like ATI, but now since doing Kaplan, I think it (Kaplan) is the most like NCLEX. But to answer your question... ATI is pretty good, we used it through out our program (for LPN) as well. For the final ATI predictor exam, I dont quite remember my score but it translated into passing NCLEX-PN the first time with 98% chance of passing. And I did. I passed 1st time with minimum (85) questions. So I think it is pretty accurate in its prediction. And so was Kaplan. The predictor said I had a 96% chance of passing NCLEX-RN on 1st try, and I did. I passed last month again with the minimum (75) questions. I hope this helps.