My LE Number is 02720 with Manufacturing Part Number (actual serial number...?) of CNA 1310L1B. Therefore, it was made in the 31st week of 2011.
The unit, with the exception of the slightly wonky shift keys, seems fine. What are the chances that it has as yet undiscovered faulty keys or some other problem, being part of the original batch? Would the firmware version of all LE units released to date - old and new - be 2011-04-15? How can I tell? Where is the Checksum indicated? I take it replacement units have the PSE bug also.
My very first HP calculator was a 15C S/N 2237AXXXXX. This new one is very fast - e.g. Valentin's third double integral example in his "Long Live the HP-34C !" article (a must have like all of his other articles), takes some 17 minutes on the 34C and not much faster on an original 15C, but computes to at least 6 significant digits in a mere 6 seconds on the 15C LE.
The HP 15C is, in my humble opinion, the best pure RPN calculator, with all functions readily accessible from the keyboard, ever made.
Jeff Kearns