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
