I keep LTSCALE at 1 nearly all the time - the times that I set it to anything else are very few and far between. But then, I almost always use the half-size versions of linetypes (like HIDDEN2 and CENTER2), rarely use the normal size versions, and never use the x2 versions. I even created my own quarter-size linetypes for each (HIDDEN4, CENTER4, etc.) which I use occasionally. I also defined my own fence linetype - those ARE way too big in Autocad's default.
Just out of curiousity, what sort of linetype definitions are you using that require an LTSCALE of 16?