refinance or not?

[Joe Jensen]

right now i have a private loan (owner financing) for a condo in St. George Utah.  

I owe 19k on the property and my interest rate is 4.8%

If i go get a loan through my credit union i can probably get a 3.8% and my private  lender said he'd give me an early payoff discount of $3,500.  So i'd only be financing 15,500 through my credit union.

I'm already 4 years into the 10 year loan with the private lender.

is it a good idea to refinance through an institution and take the lower principal and lower interest rate?

or should i keep the loan i have?

If you think i should refi what kind of loan should i get? a 30 yr? 20 yr? 10 yr?