For years I've owned a Sony Ericsson T610. It started to have physical problems last spring; for example the phone stopped charging without holding the powerconnector "just right" due to a bad power port design: the conductors on the port are on the outside, exposed to the world. These, not unexpectedly, got corroded after five or so years of constant use. But I really liked the software on the phone.
So last winter I bought a Sony Ericssson K550im . I bought it after much agonizing about features. Without looking at it closely, I figured there was no way possible that it would have as bad of a power connector as the T610. I bought it. Wrong. It did. It had an even worse connector; larger, and on the side of the phone instead of on the bottom. After six months, apparently just from holding it, the power bus corroded and it stopped charging. This was not a case where I dropped in in a toilet or had in in my pocket in the rain or something. It just plain corroded from normal every day use. The power connector is just in the wrong place; it's a bad design.
So I sent it back to Sony. They sent it back to me with a nice note telling me it was not fixable due to "water damage". Apparently for any price whatsoever, as they never even bothered to call me about it, they just sent it back to me unfixed.
So. No more Sony Ericsson phones for me. I just bought a Nokia. We'll see how that goes.