There's definitely an improvement. My left temple is around Norwood 1.75 ish . It is covered with vellus hairs here and there, so it's not totally bald. Some months ago though, my left temple was more 'exposed', meaning it had visibly fewer vellus hairs. So microneedling helped in that regard.
My right temple is Norwood 1.5, the hairs in the corner got thicker, so now when I do a comb to the right it it looks like normal NW1. I can remember months ago my right corner looked thin, I had to do an extreme combover to the right to make it look 'normal'.
Hairline density has improved slightly thanks to the serum and microneedling. When I just started the serum my scalp was more visible. Now less so, after washing there is little 'scalp visibility' under moderate lighting conditions.
Overall if I run my hand through my hair it feels like I have more of it, like it is softer and more 'mobile'. Summing up, when I comb my hair I have something to work with.