It all depends what you want a mobile phone to do. I don't use a lot of the functions packed into this phone, so can't honestly comment.

I've had it about a year without problems - so its reliable.

PHONE - works well. Clear sound. Commended.
SCREEN TOUCHPAD - works well. AND there is a separate "touchy-feely" standard keypad under the slider. Nice! No problems here for me.
AMOLED SCREEN - a great improvement. With other phones, I was forever shielding the screen from the light with my hand, or pulling my jacket over my head to get some shade so that I could read the screen. With this, the screen is easy to read in all but the brightest sunlight.
CAMERA - one of the best! I use a camera a lot at work and now never take a separate camera out with me - I just use this phone! It will make your snaps look a bit more than 'amateurish'
MUSIC - sorry, I dont use this function, so I can't comment
SYNCHING - Oh yes! It synchs with OUTLOOK superbly well! My calendar and contacts are all up to date and easily accessible. This is the phones big plus for a 'road warrior' who needs access to that kind of information. Well done Samsung! A+++++ (but IMHO, a blackberry is better for most 'road warriors')
APPS - this is NOT a 'smart phone', so has no real apps. Sometimes I wish that I had gone for a smartphone so that I could access a spirit level, a compass, a map of the tube etc. But I went for value for money rather than an expensive smartphone. My life is not exactly devastated because of the lack of apps, but it could have been a little shinier.
FAKE CALL FACILITY - well, its there and works (but do I REALLY need it?)
BATTERY LIFE - OK, here it is! This is a REAL BUMMER! I am a very light phone user - but when I do use it, its IMPORTANT. I must recharge overnight every day. I dare not go 2 consecutive days without recharging. This is not convenient, and I would not recommend this phone for the forgetful.
SUMMARY - performs all basic functions really well. Great, easy synching with outlook. Excellent camera. AWFUL, AWFUL, AWFUL battery life.