Denon x3400 to x4700

[gixer1000]

I am toying with the idea of moving up to from a x3400 to a x4700 at the moment I have a xtz power amp powering my left and right the question is will I be worth the change my other option was to buy a power amp for my front left and right and use the xtz to power my rears any advice welcome
Cheers

 

[MaryWhitehouse]

What do you hope to gain from each option? Or what's lacking in current setup?

 

[gixer1000]

I just think my centre rears and heights are lacking a bit of oomph if I bought the 4700 I would have a bit more power plus I have the option of adding front heights at a later date