I tried several times to import my Gedcom from Ancestry/FTM 2014. It’s a big one about 10,000 people.
I had FTM export to the Gedcom 5.5? format. I made several attempts to import the file. The last one made some progress:
RootsCity did appear to be trying to read the file. Took a lot more than 30 min, but there was a line racing along the border between the Blue border and the gray body of the screen.
The Name of the tree did appear on my dropdown list of trees after a long while. (something like L Beta1)
I could select the tree, but never did see any people. I decided to give it a lot more time to process.
Now today the tree in gone from my list.
I assume it choked on the large file. Do you have an intended limit for file size?
If you are hoping to attract experienced genealogists they will likely have big files.
On the bright side I went back and created a gedcom with about 550 people. It seems to have imported and I will be working with this as well as a manually created file.
Environment: Windows 10, Firefox (latest updates auto install)
Note: Ancestry gedcoms did not work well with WeRelate (imports were ugly) so I purchased RootsMagic yesterday and will do more experiments.