Just consulted my wife who is a real estate agent. She said that most people DON'T put down 20%. A lot depends on the financing. 20% will allow you to avoid PMI, so that's and advantage.
In a serious funk this week, and needed to read this.Start anonymously pranking another professional who is super uptight. Start worrying if you get to the point where you learn about sending crab lice via mail.
I put 20% down on my primary residence.
You will generally get the best rates with 20%+ down. Saves you money in the long run. And, given that home prices are definitely on the high end, a higher down payment can protect you somewhat from a price downturn and being underwater on that mortgage. I, personally, would not buy without a 20% down payment.