Well, I had been using my Nokia 3315 since around 2 years and was content enough as it is a very durable and easy to use piece. However, one problem that the Nokia 3315 piece has - in fact most Nokia phones have is that they have limited phone number storage memory. The primary reason for me to look for a second phone was something with increased storage capacity.
Most Nokia phones had a very good memory yet, the phone number storage memory is limited. I had two problems - I needed enhanced phone memory and secondly, my budget was Rs 5, 500/-. I went through numerous shops looking for mobiles both - new as well as second hand. However, nothing seemed to satisfy my need. A few cell phones did have enough memory storage but, their style and design was too ordinary. Then, the other problem I had was that no other phone provided the reliability that Nokia does and add to it the resale value that it retains.
Thus, after a lot of deliberation I finally settled for the Nokia 6600 - A second hand piece sparingly used and in very good condition for Rs 5300/-. And believe me - it is nothing short of a mini computer with loads of storage space for phone numbers - thousands! The looks and the design too is very compact.
One of my friends had used the 6600 and still refers to it as a potato - but then, I would say that it is compact enough and has some very good features and a very god choice for someone who wants to graduate to a better cell phone.
However, one must be careful in selecting second hand phones - what I did was that I got my friend, a mobile phone repairer to get the phone for me. Full marks from me for the Nokia 6600!