For a U1 mini or U2 mini, an external linear power supply is probably a more cost efficient first step. I had a T2 with an SBooster, and for me, it was a significant improvement.
To the original question, yes a PC can certainly make a difference you can hear. It's up to you to figure out which one floats your boat at a price you can live with.
I would suggest the lending program from thecablecompany.com. For a reasonable fee, you can demo multiple cables and decide for yourself. If you choose to buy, your rental fee applies to the purchase. If you don't hear an improvement at a price you're willing to pay, you're out only the rental fee.
I've been down both paths, and currently have an X1 with an aftermarket PC.