Well Ckh93, it depends actually...whether u like slider phone or juz simple candybar design phone...for me, im much prefer candybar phone as it is to me more simple and more to what a phone should be look like! haha..of course this is only my opinion and u have the rights to choose ur own favourite phone..well, let's get through to the comparison shall we??

1) The first diff that seperate the 2 phones above is their family...W595 is from Walkman series which is mainly for music dedicated person while C510 is in the Cybershot series which is mainly for photographer or some1 who likes to capture every moment in their live...well, who r u??

2) Let's compare them more specific, C510 has 100mb of internal memory while w595 only has 40mb

3) C510 has an accelerometer that w595 don't.

4) C510 has a single LED flash while w 595 don't

5) C510 is able to record video and and video telephony while these features don't support in w595

6) C510 has more coverage than W595

further info can be obtained through http://www.phonegg.com/comparison/Comparez.php?p1=912&p2=757

Hope it will help u more about that and i personally will choose C510 as im more to a person who likes to capture every moment in my life and then write it in a blog .. well , it's all up to u to choose actually!!