Review: Nokia 7510
The 7510 is not Nokia's best effort. It may be small, but the ill-conceived hinge, poor camera performance, and so-so call quality are major detractors.
The Series 40 platform is probably the 7510's best strength, but even it is showing its age lately. It is highly customizable, the media software shows more polish, but hasn't been overhauled in years.
Because it has Wi-Fi, you have an alternative for faster browsing since the 7510 can't use T-Mobile's 3G network.
The poor hinge, lacking call quality and camera are definite deal breakers for me, though people who don't care about those things could certainly overlook them.
On the plus side, the 7510 could be the right phone for you if you're into interchangeable faceplates and the ability to make calls via Wi-Fi.