I'll be honest, I've ordered stuff from them before.
And it's kinda hit or miss. I've got some really good products from them that I am more than happy with, and some products that have ended up getting sent back.
But when I sent stuff back they were very prompt with refunding me and the people I dealt with were always polite and nice about it.

I'd say that if you can get it from one of the XMarks sponsors, do it. But if not, there's no shame in ordering from Heritage of Scotland.