Mp3 playback is very nice, and sound from its speaker is reasonably loud and clear.
In-Call sound reception is also good.
Otherdifference I noted between 6630 other symbian phones like7610, 6670, 6600 is that 6630’s processor is really fast, It opensapplications faster as compared to above mentioned phones.
Now coming to the shortcomings-
I had a very bad experience with phone’s OS, which kept hanging time to time.
AlsoIf you are kind of tech-junkie who like to install many softwares ontheir phones, beware! 6630 is not very stable with 3rd party apps, asexperienced by me.
One perticularly nasty incident was when Iinstalled MobiCall.( a well known and very popular blutooth chatapp).MobiCall which works very well in 7610 and even in 6600, drove my6630 to dead piece of plastic!It absolutely refused to go beyondstart-up screen!
Only option was to format and reinstall evrything.
And same thing happened again and then one more time.In all I formatted my 6630 three times!!!!!!