I have a cousin with more than 120,000 people in his tree who uses FTM 2010 or 2011, I don't remember which - not the latest version. His online tree is showing more than 54,000 records, so less than you quoted. I don't know how many he has in this FTM tree.
His seems to work OK for him. He keeps both his FTM tree and his online tree updated manually.