Samsung 25 is a good phone. Compared with the 15, you get a better Processor, more Ram, better screen. If you want a eSim in the future, you may have a look at the A35. But I would not go less then the A25. Not worth to safe a little and be disapointed down the line. 15/25 both are not watertight (no ip rating), that will start with the A35. Just in case you like watersport Songkran.