Thank you all for your input, I really appreciate it!
My reasons for potentially choosing one of these four cartridges are price and accessibility.
My system is modest, so regarding price I’d prefer to stay under $500. $350-$450 would be the sweet spot. I’ve heard the Ortofon 2M Blue and Nagaoka MP-110 on other turntables, of the two I liked the Nagaoka better.
But I like the way the Ortofon mounts better than the Nagaoka carts, with the top screws. So my hope is to learn from someone with a Rega 330 tone arm who has actually experienced these carts. Maybe the Bronze would sound great on it, or maybe the Nagaoka is a better choice? I have no experience with the AT or Sumiko carts.
I have not had hum issues thankfully, I use the phono stage built into my Marantz PM KI Ruby integrated, and it seems solid. As a relative newcomer to this hobby, it is quite helpful to learn from all your experiences-thank you for your generosity to share what you have learned!