I love Melvin Potter. And I'll be careful to say Melvin Potter, not just because of the Shi'ar Gladiator but because, before Gladiator got a name (i.e., before Frank Miller) he wasn't that interesting (although I think there were at least hints of the character he became that Miller latched onto). As a villain, he's fine but not all that interesting. Daredevil pinned down by circular saws can be pretty intense, but that's about it. Even in the "I challenge the greatest warrior around" theme, Bullseye's fight on TV was better than Gladiator's.
What Melvin Potter has is a great redemption story - one that fits into Matt Murdock as a lawyer. Most people look at someone who kidnaps people, attacks people, etc. and thinks they deserve to rot for the rest of their life. Way too many people still view the insanity defense as "getting off on a technicality" (when, in reality, the insanity defense is successful 1% of the time and, when it is, a defendant, on average, spends more time in custody than they would if they were convicted). With Melvin, you see a success story. He's someone who, when he has help, when he is with his therapist, he is a productive member of society and an ally of Daredevil. That trial where he was acquitted transformed him from a character who was a minor threat when a villain to one who was a tragic character when he relapsed in villainy (often because he was threatened or manipulated into doing so).
I'm glad the Netflix show incorporated him and I'm glad they used the Miller insanity aspects. He really came off as a man-child that I thought sold it effectively. Even though he seems a passable genius inventor, you realize there's a lot more going for him when you actually interact with him.