For the first 2 years, the gap all-in is about 0.345% between Fixed and Floating package.
FHR is tied to DBS Fixed Deposits 8 months rate. The rate is kind of "Board Rate". I read somewhere that their is limits on how much a bank can change as there is some MAS oversight. Not sure is true and how stringent will MAS allows though. Nevertheless there is more transparency in how the final loan rate is charged.

Rationale for Fixed Package

This 0.345% gap can be closed within a year of rate rise which could make the Fixed package more attractive however the spread for year 3 and 4 will be wider and to floating method. Since the lock-in period is 2 year, i could re-price