I have used the financing. It is like most consumer/retail cards. If you spend $1000+, you get no interest for one year, as long as you make your payments on time and pay off the balance within the year. If you don't, you will pay a very high rate of accrued interest.
I set it up for automatic withdrawl from my checking account, so I'm not late on the payments, and I have watched the one year date closely, so as not to miss that one. For example, I bought about $3000 worth of gear about a year ago. I will pay the balance off next month, or will add about $750 in accrued interest charges. If I pay it off in time, I will truly have had a no interest loan for the year.