I am very curious about this also. But I did go ahead and order the kit from 23andme yesterday. It will be awhile before I can do any comparisons.
I have not tested anywhere else, other than the autosomal on Ancestry - so it seemed like a reasonable thing to do.
Like you, I have the majority of my ancestors still in Europe sometime in the 19th century, so I am not getting many matches on Ancestry, so far.