Do most front and rear USB connections deliver the same power and performance?
The location on the case is not going to determine whether it is a high power or low power port. The motherboard manufacturer can choose to provide high power or low power ports and they may be on the motherboard directly (at the rear) or just headers that are connected via a cable to the front ports on the case. It would vary depending on the motherboard and how things are hooked up inside the case.
True, there is certainly a tiny bit of voltage drop over a longer distance, but that's not going to affect the overall output much.
My vote goes to "negligible".
If we started losing power on such distances, where would our high-power electricity network wind up ?
One possibility for reduced power is if multiple usb ports at the front are actually a small bus-powered usb hub then the power is reduced from 500mA to 100mA (for usb 3: 900mA to 150mA).
Source: How to fix the "Unknown USB device needs more power than the Port can Supply" error?