I do it all the time. It only takes a few minutes. On older units the coil fins are usually damaged or clogged. It just provides more information and ammunition on a unit that is older that it may need replacing sooner, rather than later. Also, I cannot count the times that I have found burned wires or connections.
Am I missing something with removing the cover plate to examine the coil fins? I have removed it to take readings with an ammeter before but 90% of the coils fins are already visible. You can see them from the outside and look at the inside past the fan.