Ok, so I've been using the standard BC icing recipe with crisco for a few years now, and I've always had issues with smoothness, air bubbles, you name it. A month ago I went to my best friend's wedding out of town, and fell in love with the light fluffy BC they used, and found out what it was they used to make it.
IT"S AWESOME!!! I will never use crisco again except to pipe designs and borders!!! the recipe I got off of here, its the swiss meringue BC, and it smoothes out so easily and nicely, and is very light and fluffy!! I HIGHLY recommend just trying it out on a play cake, and I will almost guarantee that if you have problems with smoothness before, you will use this stuff from now on.
Please please please if you don't like BC, just try this stuff. Looking back at the other cakes I did, I wish someone had told me about it sooner.

Does it crust? Can you get on the cake and smooth it out?

Merengue buttercreams scare me! They seem a little complicated, having to keep everything at a certain temperature, adding things slowly - I would be afraid I'd do it too fast or having something at the wrong temp and screw it up!

None of the meringue b/c's crust.

The "hot spatula" method is usually used to smooth.
(A lot of ShirleyW's cakes are IMBC.)

Here's ShirleyW's IMBC recipe:
(Uses less butter than most IMBC recipes.)

http://www.cakecentral.com/cake_recipe-2426-Italian-Meringue-Buttercream--Shirleys-Method.html

How to professionally ice a cake:

http://forum.cakecentral.com/cake-decorating-ftopict-82411-.html

(And most keep the mbc frosted cakes refrigerated - allowing sufficient time for the frosted cake to be able to come to room temperature before serving.)

Here's an easy faux mbc recipe that starts with marshmallow fluff:

http://www.cakecentral.com/cake_recipe-2110-Marshmallow-Creme-Buttercream.html

HTH