0% interest for the life of the loan is something you should use for all but the most trivial of purchases. It's effectively reducing the price of the product by several percent, since you'll be paying for it with inflated dollars as time goes on. And that's even if you don't do anything with the money but stick it under your mattress. Could also put part of it into some short-term CDs or T-bills (interest rates are great right now) and put that loaned money to work for you. Hell, you can even get north of 3% interest with some savings accounts now.
I'm probably in the market for a new phone this year, and I'd absolutely do the 0% 24-month financing even for a "normal" priced phone. I get that some people are debt-averse, and I understand why, but if you can afford to pay for this phone outright, shying away from the financing plan is irrational.