In my family, that was a popular tartan for the same reasons you list, Janet.
Then, we were in a Scottish shop here in New Hampshire, and they pointed out the Maclay tartan to us, and so then my family bought some items in that tartan.
When I was looking to get married, I looked at all of those... Stewart of Appin, Maclay, and Livingston Modern and Ancient.
And because I'm so considerate (

Given my new role as Commissioner for the Clan, this has turned out to be quite appropriate. But I think given our historical alliance with the Stewarts (esp. of Appin) and our ties with the older Mclay name--the other choices are also quite appropriate (including the hunting Stewart).
And as Donald has pointed out, the historic nature of any of these is up for question, regardless.
I think that tartan in its modern incarnation should be used as it has been used the past 100-200 years: as a (perhaps artificial, but real in some sense) marker of identity. And since we all have different aspects to our identity, our choice of tartan on a given day may reflect different aspects of that identity. One day, we want to show our historical relationship to the Stewarts, another assert our individuality as McLeas. It's quite a color pallet out there!
Kyle=