The Good:
Radio
MP3 player
Recorder
QWERTY keyboard
Softwares and cables come in the package
Cheap phone
The Bad:
No color screen
The size
No polyphonic ringtones
No ringtone (and picture) composer
No external speaker for MP3 player
The Nokia 5510 is a decent phone, good features. The only problem with it is that it is a comparatively big phone (Weight - 155 g : Dimensions - 134 x 58 x 28 mm, 165 cc ). This one is a dual band phone (EGSM 900, GSM 1800, and GSM 900/1800 dual-band networks in Europe, Africa, and Asia Pacific; automatic switching between bands).
The QWERTY keyboard comes in very useful when sending SMSs (but the 6820 has a foldable QWERTY keyboard, so.....).
The MP3 player is superb. The clarity is excellent. It also has 64MB space to store music (about 2 hrs of music). It also plays protected AAC and MP3 files.
The radio is pretty good. Due to the fact that the antenna is in the hands-free, disturbances will be present which can actually get irritating, especially when you are listening to your favourite song on the radio station.
The recorder records from the FM radio or an external audio source via line-in cable, for example from CD player.
The absence of polyphonic ringtones is disappointing (but then, this phone was released over 3 years ago, so....).
The Ultimatum:
This is basically a Nokia 3310 plus the goodies.
Since this phone has become old, I wouldn’t advise you to get one (Though you may get one to feel different, if you want to ;-))
This is otherwise a very good phone.
By the way, you other reviewers haven’t noticed that the phone picture is wrong???