We bought the previous model, the PRS-300, and were very pleased with it. The new PRS-350 model is much better. It is smaller, has a touch screen and the very convenient dictionaries - which can be configured to use as a holiday language translator. Not having a basic cover provided with it (as per the 300) was a slight nuisance. But I bought the expensive but very classy looking Sony leather faced cover. It looks very smart in navy. I also bought a separate charger, for when I don't take a laptop because of lack of Wi-Fi. I bought a cheap non-Sony charger which works fine. I am sure the battery doesn't last as long as the previous model.
However the stylus is a poor design and very fragile. Mine broke after a few weeks, and not through rough use. Sony don't accept this is a design flaw, and your eyes will water at the cost of a replacement! Waterstones and Sony did not impress with their customer service over this matter. (Web searches showed that this failure is a common problem, and Sony soon stopped providing replacements on guarantee.) However my wife provided me with a plastic knitting needle that when cut down and the end smoothed off provides a neat & well fitting replacement. Size UK 9, USA 4, 3.5mm. It looks surprisingly good in the device, and provides a reminder of Sony's design fallibility!
Despite the above, the reader is a really elegant device, slipping into a jacket pocket. I'd rather have a smaller device, than a larger one with wi-fi capability etc. Our local library commendably provides an e-book download service (free) and this is a big advantage, for us, over the Kindle.
My wife was extremely sceptical about e-readers, but is now a total convert. An advantage for her is that by increasing the font size she doesn't need to use reading glasses.