Thats right - before I talk about anything else, let me say it again - it weighs only 70 grams. You wouldnt feel you are holding anything.
My wife had a Motorola V3 for the past 2 years - during the last week or two, the V3 started behaving erractically - dropping calls and showing extremely low battery(altough, the battery was always the problem). This time, she decided that no fancy stuff would do - only Nokia can survive the test of time.
We were looking at 6300, 3500 and 5310. After looking at mouthshut and getting reviews from owners of 6300, we decided to opt for 5310. This was a very good decision.
The phone is so sleek and feature-packed(no infrared, but then who needs it). The Nokia Priority dealer also leaned towards this model inspite of having pricier models.
Now since this phone is also a music edition, we got a bonus - since we had not planned on getting a music phone. And the sound is really good through the headphones. Almost the same as an ipod. The speaker sound is although less on the bass, and not that good.
Another good feature is the 512 mb memory card, which ensured that we do not have to spend extra money on it. The battery is also the famous nokia long-laster - no problems on that area.
However, one con about this phone is the camera quality - actually the camera clicks nice pictures, but the shutter speed is set to too low - as a result of this, we have to hold very still to click a perfect picture. I am still not sure if we can increase the shutter speed in it. But I have seen the same problem in many of the latest Nokia models - so have almost accepted it as a fact.
To sum up, its sleek, light-weight, feature-packed, and a great buy.