It seems that Slicehost DNS doesn't offer AXFR, but it does have an API.
I have about 20 domains in Slicehost DNS and I'd like to automate the export process if possible.
I've been trying to figure out how to export the records as zone files, and I tried this but it doesn't export the full zone file.
Can anyone recommend a way to get the full zonefile out of slicehost (or avoid having to manually re-enter them into DNSmadeeasy).
Update:
I spoke with Slicehost support about it. They said, make a ticket, they might be able to export to bind for you.
Original Answer:
I don't think there's anything better than the one you found. I think you'd be best off hacking the script a bit to get more out of it.
I expect though that the reason it doesn't give more is more likely to be limitations with the api though.
These other scripts, which do less than the one you found might be useful in hacking the first script:
https://github.com/mattly/slicehost-dns
It dumps to a yaml file, then you could run some vim macros over it to turn it into a zone file.
https://github.com/Schultz/slicedns2linode/blob/master/slicedns2linode.rb
API Docs: http://www.slicehost.com/docs/Slicehost_API.pdf