Rubinstein recorded the Chopin catalog three times. The first was in the 78 era and was a fiery, more daredevil approach. His second cycle was in the hifi era, and that one is wonderful. Perfect mono sound, which is best for piano music on speakers. The last set was on Living Stereo and is among the best sound ever put on record. By this time, Rubinstein was magisterial, with formidable technique and complete mastery of the subleties of the music. in particular, the 60s Nocturnes have never been equalled.
You need to look at the recording dates. You want the cycle recorded in 1961-1963 or so. I have the complete Rubinstein box set and without question, he was one of the giants of the 20th century. No one compares. Before him, Chopin was seen as puny music for little old ladies with lace doilies. Rubinstein saw Chopin's music for what it was... an expression of the Polish people. And if you know anything about Polish history, you know how deep that runs.
Even if he was recorded poorly, Rubinstein would still be a first choice. But luckily, he was recognized in his time and got the finest engineers and equipment available. His career spanned the entire 20th century, and the complete box set is 170 CDs. You need to know what you're buying if you want his most recent recordings.
That said, if you like Chopin, you owe it to yourself to get Rubinstein's Moscow concert. He was asked to play in Russia and was reluctant because of the bad blood between Poland and Russia. He eventually decided to go, and the concert was captured by two local TV cameras. It is one of the most electrifying performances ever. He went on stage to perform a program of Chopin and ended up channelling the defiance and bravery of the Polish people into the music. The nocturnes and etudes are spectacular, and the performance culminated in the Heroique Polanaise- a performance that has to be seen to be believed. The video is available at Netflix and Amazon, and it's the single greatest live classical performance on video.
http://www.amazon.com/Classic-Archive-Rubinstein-Legendary-Recital/dp/B001IMFHVG/ref=sr_1_1?s=movies-tv&ie=UTF8&qid=1348787551