I've had a Sony machine for ages (a superb wee 505), but I dumped the Sony Library early on and have used Calibre exclusively.
Another grouse I have with Sony this week, though, is that we just signed a contract with Sony to carry our own indie publishing house's full catalogue -- usually about 130 current titles -- and they claim an outrageous 60% sales commission, even though we upload our own files. That level of commission is penal even in brick-and-mortar stores that carry treebook stock.
And folks wonder why most of the bigger houses insist on an Agency 5 model to maintain a realistic cover price. Those publishers like us who prefer to opt out of Agency 5 to set low prices on ebooks are hammered.