re: sony, the 650s are nice but they can die. One did on me after 14 months. I got a couple of backups from ebay very cheap. I never use the standby function because the weak point of the design is the power-button.
The 505s are very durable, but you may need to change the battery.
Don't know about other products. Maybe one of the smaller companies produce something designed to last more than a year or two.