I'm back with an update on upgrading the backup lights to LED. The first ones I tried from iJDMToy were OK but due to the single outward-facing LED and projector lens, the beam was more focused and narrow than I wanted. In addition, without side-facing LED elements, the built-in reflectors in the Depo tails weren't being utilized. As I reported previously, those bulbs which were advertised as error-free were not and I had to install load resistors.
A couple weeks ago I saw this ad from iJDMToy and was intrigued by the different design and higher wattage output:
http://www.amazon.com/dp/B008G4Y076/ref=pe_175190_21431760_3p_M3T1_ST1_dp_1
Subsequently, I bought a set of those and installed them. IMO, these are much, much better than the previous bulbs, mainly due to the total higher wattage with front AND side-facing LED elements which utilize the Depo built-in reflectors. As an added bonus, these bulbs are a bit shorter and seemed to snap into the sockets better. With this upgrade, I am finally satisfied. BTW, the load resistors I used were also from iJDMToy and were 8 ohm, 50 watt. These are fairly small, easy to mount, and are wired in parallel with the bulbs.