why would anyone take 30 year fixed...

[Roy Mitle]

... over 5/1 ARM for investment property

Right now the 5/1 ARM seems to be 1% below 30 year fixed (lets say 3% and 4% for argument sake)

For the first 5 years I am saving a large amount of cash. After 5 years 2 scenarios

a) Rates are higher because the economy is on fire => I can get higher rents to offset the burden. Note my break-even point is 5% so rates have to be higher than 5% for me to loose money with ARM over 30 year fixed. Simplisticly speaking my rate has to be 5% for the next 5 years for it to be a wash (I saved 1% for 5 years with ARM and lost 1% with ARM over next 5 years). Is this right?

b) Rates are lower or same so I am anyway better of in the adjustment period.