It's just another entity to deal with. More time to process and another company to make calls to if you need something done. I was in a wreck and needed things processed for a new car ASAP. When the car arrived off the docks and was delivered to San Diego, my loan processed that day and I drove home. Many banks and credit unions may take a week (or two or three) to process the loan. I'm not sure the details cuz I haven't gone through the process in a long time, but my mom has worked in banking and lending for 30 years, so I take her word for it. It's not a problem and you will definitely get better rates than going through the dealer. I just wanted as few steps as possible as quickly as possible. And since I had such good credit, the difference in monthly payment was less than $30. Also, 1.74% is amazing.
You can compare what your payments would be yourself using a loan calculator as well:
http://www.bankrate.com/calculators/...alculator.aspx
You can plug in different values for down payment, rate, length of loan, etc. See where it puts you for monthly payment and see if that fits in your budget.