balanced vs. unbalanced sound quality

It depends on which preamp you are using. Does your preamp have XLR outputs? Or are you trying to use a RCA-XLR adaptor with a balanced cable?

One thing I would like to make you aware of. If by "higher end" you mean higher price, it doesn't automatically translate into better sound, it only means higher price.

This debate comes along often. It really depends on the components involved as there are numerous varibles. For short cable runs there`s no clear winner(very long runs favor balance cables).Some of the very best cost no object components are single end design per builder preference. Try both and see what you like best.

Jdub39 - I don't have a lot of experience with balanced vs. unbalanced, but I did have an amp that used both. When I first tried balanced it sounded much better, but then I realized that the balanced connections have more gain, i.e.: The music was a little louder. I believe much (maybe not all) of the "Balanced is better" is due to the increased gain.
So, did you level match?

Nineballg - I use 0.5m balanced with class D amp. Balanced cables have locking connectors. In addition they use male/female connectors preventing accidental touching of the input (exposed input always female).

to a certain extent it is almost pointless to ask other people what might sound good to you. while the quality of sound of balanced vs. unbalanced inputs is dependent upon the quality of the components as pointed out in another reply, from my perspective, you tend to get better sound from xlr inputs. it is true that you get a higher signal level from xlr output, but components of which i am aware tend to attenuate the xlr input signal to compensate. however, the higher signal also results in a better signal to noise ratio, so the signal might sound a bit cleaner. that said, don't expect the difference between balanced and unbalanced inputs to be "night and day".