Well...salt vs no salt, I definitely have to say salt. Like you said, it draws more out of the hide, where glaze drying is more of a surface drying. Salt helps deter any bacteria growth also, which is my biggest concern with the volume I deal with, but even for a single unsalted, poorly fleshed hide, the bacteria rate is going to be high.
I feel like broken record preaching this, but bacteria means slippage, no matter how good you are.
Non-Iodized vs Iodized!~~ to be honost with you, as far as what you and I are using it for it makes no difference. The only reason they put iodine in salt to begin with is to make it safe for human consumption. The effect it has on tanning or drying is very little to non.
Besides the iodine that is added to iodized salt, some salts have other chemicals added to prevent clumping, etc. SOME of those other chemicals can actually act as a buffer when your trying to adjust the PH levels on your tanning baths.
As far as drying hides...they both work equally well, regardless of what someone else tells you. /ubbthreads/images/graemlins/wink.gif