HELOC question - which should I get?

[Amy Parra]

I'd like to get a HELOC lined up. My bank offers two kinds:

1. Equity Line Plus Interest only 
2. Equity Line Plus Principal and Interest
   

- Could someone explain why I would want to use one over another? The explanation for 'plus principal and interest is' - the same except it adds the qualifier "with an affordable payment of 1.5% of the balance."

Thank you for your advice!

~Amy