I don't know about Elvis (I haven't had time to listen to these selections of yours, I'll do later) but you're under heavy killing artillery for comparing Cat Stevens to this Boyzone guy. Not because you may have different musical taste but because your comparison is unfair. You picked up a recording by old Yusuf (former Cat Stevens). Yusuf's voice is a far far cry from his younger incarnation, and you implicitly implicitly suggested that this is the original of the Father and Son. I'm sorry, your pick was a grave mistake, as it was not the original. This is the original, by Cat Stevens:
Superb singing, superb rendition of emotions associated with the lyrics (including the rise by an octave in the chorus, at 1:25), Boyzone is just a lifeless non-emotional automaton, a poor (although technically clean), failed try to imitate. Legally, Boyzone could afford this imitation, only because Yusuf decided to renounce all copyrights to all artistic creations of his former self.
If you still disagree with me here you are under my killing artillery fire with more detailed arguments to come.