Reply to MacBook Pro SSD Retina is it worth for Production?

After my decision to start with music production, I am going to change over from my current MacBook Air to a MacBook Pro. Main reason is that my Air does only have 2GB RAM and a 64SSD drive which is not enough at all. On top of that, it's just an 11.6" and it also has less ports.

Does it make sense to go wit an older Pro model instead of a brand new one? I don't see any big issues with an older CPU as it's at least an i5 @ 2.5Ghz.

However, I am not sure about the SSD drive and the retina display. The SSD is much faster than a traditional 5.400 RPM hard drive, but I am not sure if it is worth? Same thoughts on the retina display. As the retina has a much higher resolution, does it just bring much more sharpness, or will you get more on the screen in total?

Thanks!