Hitech M21 has excellences such as good voice quality, just because Hitech M21 is music celullar phone so voice quality is noticed. In other hand Hitech M21 also can be used as modem by using GPRS class 12. Song format can be played is many for example MP3, AMR, WAV, IMY and MIDI.
Whereas the weaknesses of Hitech M21 are for example there is radio FM but to listen to it must wears arphone, small battery capacities and camera result is less.