no

A couple of people I know use a Hipshot drop D tuning peg. I have borrowed the bass of a friend on occassion who uses one of these. I find that his bass maintains tension on the low string in both the regular E and drop D positions, because of the special nature of the peg. I drop D tune my bass on occassion (doesn't have the hipshot peg) and it does lose it's "springyness" a lot faster. Just my $.02.

I have three (crappy) basses.

I keep one in standard at all times.
One in drop D
And on the third every thring is down 1/2 a step, because thats what we play in (vocal range issues)

My guitarist reccomended a fella' who set up my truss and action and stuff when I first started.

Well, I took them to him and he changed the setting on the action (I dont know about the truss) to suit the tunings.

So apparently the action can help.
I am assuming you highten the action when you tune down to compensate for the slackness of strings.

Also,
I used to hate alternate tunings. till I really went with it on a whim and found all sorts of ne things!
I read that, mathmaticially speaking, there is nothing left on guitar you could play that has not been played.

So although bass is younger we must assume this has to be true for guitar as it has less strings.

So that is one reason people tune differently.