They’re not the same, there are (at least) two different tunes per 5.x

For each you can use it as “instant” supposedly without thinking (though these are all exclusively reasoning models) or specify a reasoning amount (low, medium, high, and now xhigh - though if you do g specify it defaults to none) OR you can use the -chat version which is also “no thinking” but in practice performs markedly differently from the regular version with thinking off (not more or less intelligent but has a different style and answering method).