I am using this phone from last 3 years and never face any problem only once I had a memory full problem even that was solved with an software update.
N73M has a good sound quality and is easy of use as all Nokia phones are.
Only problem is the look of the phone. It is not that good looking as one might expect while spending so much money on it.
With expanded memory support it allows one to store many games, music and evn video on it.
The best feature is that you can use the phone as pen drive along with its cable and by putting it on offline mode you can use the phone as a player or a gaming device without any interruptions.
It also has a strong body and u can drop it as many times as you like but it will never open up or break.With expanding memory sometimes it gets slow but overall performance is ok