reamp or just aux

[feyshay]

For this reason:
Use you aux to send and turn your amp up. Listen carefully.
Then try a Radial X-Amp to do the same.
I think you'll notice a difference in preservation of the signal (especially on high and low frequencies--unless it is a placebo effect). The Aux will also likely be noisier and easily noticed when you get some gain on the amp.
Best thing you might want to do is get a Reamp box and try out for yourself. Take it back if you notice no difference.