Buying as secondary residence Vs Investment Property

[Vinoth Amar]

I live in CA, I'm planning to purchase a SF home out of state. I will mostly use it for rental but considering it as a retirement home.. I was given option by lender to close it as secondary home loan and then rent it out. I know lot of people are doing this to get low interest rates with conventional 30 year fixed with only 20% down or less. Can you let me know if i will lose any IRS tax benefits by not declaring it as a rental investment property. Are all rental expenses applicable to secondary home rented out for full or part of the year. How about depreciation cost in tax deduction. I just want to understand if there are any benefits i lose other than getting lower interest rate.