I haven't seen the 20g loading dose recommendation on anything recently either. Everything I've seen just recommends 5g/daily.

My regular supplements that I've noticed made any difference is: creatine, vitamin D, and fiber. With vitamin C and protein being situational as needed.

I feel the same way about creatine (and increasingly protein).

One thing that might help me notice creatine more is that I haven't drank much caffeine for some reason.. and the longer I've been able to put it off or minimize it, the more of an unfair advantage it has become when I've started.