Here's a link to Toba Garrett's Decorator's Buttercream:http://www.epicurious.com/recipes/food/views/109260
I've used both Crisco and Sweetex in this recipe and I don't remember a big difference in taste or texture. I don't use the fresh lemon juice or lemon flavoring. I usually just use vanilla or a mixture of vanilla and french vanilla extracts. I am interested in using a clear liqueur like pear-flavored Schnaaps for the liquid, but so far, I've used just milk.
Here's a link to her Swiss Meringue:http://www.epicurious.com/recipes/food/views/109239
At the end of this recipe she has a note to subsitute some of the butter with hi-ratio shortening. I do this no matter the weather. My family isn't too keen on the buttery taste of most Swiss Meringue Buttercreams. The shortening makes it a tad less buttery. I've used rum (and vanilla) to flavor this and it was really nice. More often than not, I just use vanilla. In my house, this buttercream is prefered on chocolate cakes (as opposed to white or any other flavor cake). Though, my kids still prefer the Decorator's Buttercream.
Also, I've used Sugarshack's all shortening-based recipe (that is posted on this board, I believe) and it is great. I use french-vanilla creamer with it. It's my favorite all shortening buttercream.
Sorry so long.