Are these beds the ones that do both 12V and 24V?
Could the people complaining it's slow be hooking the 12V up to the 24V pins?
Also, if you're using electronics that have a PTC fuse, you may find that at high currents the fuse is dropping a volt or so. You might want to look at replacing the PTC fuse with a standard in-line fuse. Measuring the voltage across the bed at the electronics end is also a good idea (as is at the board itself - you could be losing volts in your wiring).
Could the people complaining it's slow be hooking the 12V up to the 24V pins?
Also, if you're using electronics that have a PTC fuse, you may find that at high currents the fuse is dropping a volt or so. You might want to look at replacing the PTC fuse with a standard in-line fuse. Measuring the voltage across the bed at the electronics end is also a good idea (as is at the board itself - you could be losing volts in your wiring).