Old Pentax vs. Old Nikon

Any current or former film buffs in here? I normally shoot a 5DII, but when I want a change of pace and that film look, I'll go to my old Pentax MX and SMC-M lenses (28/2.8, 50/1.4, 135/3.5). I've been very happy with it, but then my uncle planted this seed in my head that has me wondering. He said that back in that era, Nikon was considered the gold standard, then Canon, Minolta, Olympus, then Pentax. I'm 36, so I wouldn't know. Is this true? I get great results from my Pentax gear:

How much better could a Nikon be? I'm thinking of getting a Nikon FM2 to find out.