Suppose we need to decide whether to invest into a 5 years bond which current YTM is 2,5% or into an investment certificate which yields 4,5% for the next 4 years.

In order to do an apple-to-apple comparison, is that better to calculate the TIR of the certificate (which is the equivalent of the YTM for the bonds) or find the NPV of both investment opportunities? And for any investment decision, is that better to use the NPV or the TIR?