DNAGedcom.com has new tools for subscribers, for downloading AncestryDNA data. Thanks to Cora Lou for this link, which describes the tools:
I tried it out. My main problem was being a Mac person in a PC world (since 1984!), but I will try to overlook that.
The match file has the correct number of matches - 5181. The ancestors file took about 3 or 4 hours to download, and has 306,346 lines. For comparison, the last Snavely ancestors file I downloaded, two months ago, had 253,411 lines, so - in the right ballpark. I haven't played with it, but it does include a column labelled "relid" which appear to be Ahnentafel numbers for the ancestor, and also includes birth places and death places.
The shared cM in the matches file is most interesting, since it reflects post-Timber measures. Here are 26 matches who transferred to other services (mostly gedmatch):
Either phasing or Timber or both might account for the differences. In one case I'm pretty sure it's phasing, and Ancestry has it wrong: a 5th cousin where AncestryDNA shows 23 cM and 23andme shows 56. This is one long segment, and the individual's mother has tested at AncestryDNA, but not 23andme. She shows 63 cM. I suspect the son inherited the whole segment, or most of it, but Ancestry phased his wrong. Yes, this is a match from a family with a lot of endogamy. In fact, I think all of these are.
Late edit: For gedmatch, FTDNA, and 23andme cMs I included only segments over 7 cM. The relationship listed is the closest one, "+" indicates there is at least one more, more distant relationship.