These are always fun discussions. Some understand, many don't, and hardware is an unfathomable black box to most.
In any computing platform, there is variable encoding and there is variable rendering. For DL PLCs, there are 3 primary encoding formats: 2s complement integer (aka 'binary'), floating point, and BCD. Within the binary encoding, there are many possible renderings...decimal, octal, binary, and hex. The decision to render I/O references in octal in no way affects the encoding, but was chosen to simplify slot addressing. The mention that octal is useful for low-level development is exactly correct and precisely why octal was chosen for I/O numbering.
Is octal best? That's highly subjective, but in fact is the whole reason for this poll.
I'm still reluctant to go into detail, but I will say that those of you who like decimal I/O will like where we are going. The new PLC that Host is developing uses decimal numbering everywhere it makes sense, and only uses octal where absolutely necessary: in memory types that are specifically provided for interface with existing DL hardware. Integer constants, on the other hand, can be entered as octal (0NNNN), decimal (NNNN), or hex (0xNNNN)...whatever is best for that particular value. I would personally routinely use decimal and hex, although octal tends to get used only for compatibility with octal I/O...which for the most part won't be present.
So...in short...we listened, we heard, and we're doing something about it.