Now that you have an opinion on END:SPR builds, I'll give my two cents as a STR:END cleric.
Simply put: I do way more damage than a cleric with no points in STR. I do on average 50 damage higher than a cleric my level, and that makes solo grinds very effective.
Though you may want to invest points in SPR for the critical rate, it's ultimately up to you. Points in STR guarantee higher damage, but criticals are literally luck shots that do double damage. It boils down to reliability.
I even crit more than clerics with 25 points in SPR. But I cheat a bit...my hammer is 5% base critical + 8% critical as of now.
