Which of these two mobiles is the best for simple text/Calling

Have a contract with Virgin for 300 texts/300 minutes for £10 a month

But use my own phone the Nokia 5200, yes thats how much i value mobile phones.

Anyhow can upgrade to £12 a month and get a new phone off them, the two ive been looking at are the Sony Ericsson W595 or the Nokia 6600i

Just want to send texts easily, and make calls.

Dont take photos or play music, dont access the internet but do use my phone as an alarm clock to get me up when on earlies so that requistie is a must.

Any phone buffs help me out?