"A study conducted by market research firm J.D. Power and Associates has found that “Nikon Pro Series” DSLRs rank highest in customer satisfaction. The company surveyed 4,500 verified online DSLR buyers to find out their satisfaction across five factors: image quality, durability, features, ease of use, and responsiveness."
From: http://www.petapixel.com/2011/07/19/nikon-ranks-highest-in-online-customer-satisfaction-among-dslr-buyers/
Via: http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=38944858
Actually, Pentax K ranks No. 5 amongst 7 with a "just-failed" mark of 883 below the passing mark of 887. Nevertheless, the K is still ahead of the Canon Rebel as well as the Sony A, which is ranked last.