I tend to believe that these differences, on what some would consider the same chip, make them DIFFERENT chips. I don't "go out of my way" to acquire every variation. I DO, however, keep one of each if I come across them.
To quote Mr. Trimble "You have waaaay too much time on your hands".
Don't worry, that's really not an insult. If it is, I've been insulted a LOT!

Best Regards,
Murph