Need your advices for upgrading!

Hello everyone..

This is my first thread in the forum!

Now I'm using MacBook Pro 13'' 2.53 Ghz Dual Core 4GB RAM notebook. I'm now planning to buy the Retina Display 13'' as you may wonder. I can compare everything.. It makes sense to have it instead.

The 8GB Ram will make difference of course. Except that, the only thing I need to be sure is the processor. In my 2009 MB Pro, I'm having 2.53 Dual Core. And in Retina, there is max. 2.9 Ghz Dual Core. Does it really make difference as performance which I can see? The thing I want to know is that the 2.53 Dual Core in 2009 and the 2.5 Dual Core in Retina are same? This having i5 and i7 are making a difference a lot?

I hope I was able to explain what I try to learn.

I'm only playing Football Manager on the MBP. Except that I'm an heavy internet user.

Thanks to your advices from now on!