I have both the checkered and smooth grips for my EB:
Both are beautiful - but if I had to choose between the two, I'd go with the smooth. The structure of ivory allows for a substantial grip on the polished grips even with sweaty hands. And if the ivory is of high quality then the depth and grain are more readily appreciated on the polished grips.
The checkered grips are by Dan Chinnock and the polished are from The Boone Trading Co.
Note too that even if the ivory is "stabilized", checkering will enhance wear; it isdental material, after all.
And as both NDL and OhShot! noted, ivory has a good "tack" even when smooth, so checkering isn't even much of an added aid in gripping the pistol, not to mention that effective grip is mostly at the forestrap and backstrap with a typical 1911 hold, anyway.
I've got four sets of elephant ivory stocks on different 1911s, all smooth, all from Mike Poulin.
My own vote for the ideal is front strap and mainspring housing checkered at a sharp 25 lpi and smooth ivory grips. I'm happy with 30 lpi on the front strap and prefer to install a mainspring housing with 25 lpi and a lanyard lug. I'm content though less happy with 30 lpi front and rear and smooth ivory. As I age and my hands get softer smoother checkering suits as my hands can be torn up by checkering they would have ignored when I was a horny handed son of toil.
Smooth ivory is my number one choice for carry though I will swap things out for high round exercises and courses - that's a good time to soak the ivory in mineral oil while it's off the pistol.
I would not be at all happy with smooth front strap and mainspring housing and smooth ivory on top of that.