I've had one of these about a year now and I'd be very reluctant to part with it. It's become part of my life and is more important to me than my mobile phone. I originally bought this as a present for my wife, but after I'd played with it, kept it for myself.
First, the device:
The design is well thought out. You can find what you want quickly and intuitively. You can pass it to someone that's never seen one before and even they can use it after you've told them to press the "DICT" button. It's that easy. When I first got it, I wasn't too keen on the screen, which I thought should be higher resolution, but actually, the screen is good enough to do its job. Battery life is excellent: I use it every day and still haven't had to change the battery yet! One of the best features is you don't need to turn it on: you just press "DICT", "THES" or "QUOTE" and it's ready to do what you want. It's quicker and easier to use than a paper dictionary. I use the "DICT" function 98% of the time, but don't regret buying the more expensive model. When you need "THES" or "QUOTE", it's very nice to have them right there in your pocket.
Second, the content:
I own and have used many different dictionaries, ranging from kiddies dictionaries, through to the monstrous and intimidating 20-volume Oxford English Dictionary. I can honestly say the Oxford Dictionary of English, which this device contains, is the best dictionary I have had the pleasure to use. It is comprehensive, yet unlike other dictionaries of similar size, it's easy to understand. This, to me, is very important. What is the point of looking up a word if you can't understand it's definition? If you can't follow it, you are none the wiser. The dictionary Sharp chose to put in this device is what puts the PWE500A head and shoulders above the rest.
Like the telephone, every home should have one. Maybe every pocket.