Speaking from experience, as I've owned both the TGP-5 and TGA-5200, they're decent gear (and the amp gives you the option to mimic a tube amp in some respects). I just sold both the pre/pro and amp over the past several months. During the time I owned them, I also owned a Musical Fidelity A5 and a Musical Fidelity A308 (both integrated amps).
The differences between the Sunfire and MF amps were on the subtle side, not a "wow" change at all. They sounded a little different, but neither provided you a huge leap in detail or clarity over the other with all other things being constant (though they are different animals, the 5200 being class D, the musical fidelity amps being class a/class a/b I believe).
One thing you're dealing with here is the use of a pre-amp. The only time I discerned a big difference in detail or dynamics was when I removed the pre/pro (or any preamp) from the signal chain and used either a DAC with volume attenuation or in my case, a computer, to control the volume. The pre/pro, while it does a good job, will "dilute" the source signal, as do most preamps that I've used or encountered (unless built directly into the source component like a DAC). This was the same scenario when using the Musical Fidelity amps where I bypassed the onboard integrated preamp and drove it directly through it's "home theater bypass" inputs.
The only time I got a wow factor out of changing amps was going from the afore mentioned equipment to a tube amp, but that's just a different sound altogether (and not necessarily better to some people). The wow factor to me came from never having owned a tube amp before.
Much like power cords, ICs and any other piece to the equation, most changes aren't wholesale improvements, just incremental steps in one direction or another (and not always forward or for the better).
The differences between the Sunfire and MF amps were on the subtle side, not a "wow" change at all. They sounded a little different, but neither provided you a huge leap in detail or clarity over the other with all other things being constant (though they are different animals, the 5200 being class D, the musical fidelity amps being class a/class a/b I believe).
One thing you're dealing with here is the use of a pre-amp. The only time I discerned a big difference in detail or dynamics was when I removed the pre/pro (or any preamp) from the signal chain and used either a DAC with volume attenuation or in my case, a computer, to control the volume. The pre/pro, while it does a good job, will "dilute" the source signal, as do most preamps that I've used or encountered (unless built directly into the source component like a DAC). This was the same scenario when using the Musical Fidelity amps where I bypassed the onboard integrated preamp and drove it directly through it's "home theater bypass" inputs.
The only time I got a wow factor out of changing amps was going from the afore mentioned equipment to a tube amp, but that's just a different sound altogether (and not necessarily better to some people). The wow factor to me came from never having owned a tube amp before.
Much like power cords, ICs and any other piece to the equation, most changes aren't wholesale improvements, just incremental steps in one direction or another (and not always forward or for the better).