I lean more torwards Valkyria Chronicles for now, mainly because it's cheaper, otherwise, I'll probably buy them all eventually.

Also

Is tales of symphonia worth the purchase? I mean, has the game aged well or not?

Symphonia isn't worth the purchase imo. I didn't think the 3D Tales games were ever good until Tales of Graces F when they gave it a faster paced combat system. Xillia has that same type of combat system.  The storylines in Abyss and Symphonia certainly don't make up for it either.

*edit*

Although just for clarification on this post.  I've finished Abyss which was released after Symphonia.  My opinion on Symphonia was a few hours of playtime but I haven't gave it another chance.  Just incase I give it another chance in the future and think it's a great game, but I'm then quoted saying I didn't like it.  :P.  Though I can guarantee it's not as good as Graces F combat system.

Most of us won't be this good, but here's what's possible in Graces F combat system. 

https://www.youtube.com/watch?v=JrI7i0Qu-Q0
https://www.youtube.com/watch?v=-KTu4mqzhAw
https://www.youtube.com/watch?v=LuMdkH2u_Jg
https://www.youtube.com/watch?v=QYLagiQ_xNA

I would go for Tales Of Xillia, playing it right now and it's amazing. I'm about 18 hours in and am hooked. It was so good I went to my local Eb games and pre ordered Xillia 2 collectors edition which is $220 NZD.

Havent played the others, but VC was brilliant. I was devo when the sequels went to PSP.