You talk about comparisons that are a good thing, and that's great, but there's a whole range of them that I personally experienced.
There's the ones that make me feel happy, like when my stuff is compared to series I like. (Trigun for example) I like to put subtle references from the animes I enjoyed, and it feels great when people notice that, and be polite about it.
Then there's the comparisons that are kinda ok, when people compare my characters to the ones I never knew about, but they feel excited about it, so it's ok I guess. I get a bit uneasy thought that I may accidentally make mine too similar to the ones I don't know about, which leads to:
The rude comparisons that you feel like being judged or accused of your characters being a rip-off.
And then there's the comparisons when people compare their OC's to yours and be really annoying about it. Like "oh no, your OC has hair like mine, ZOMG I have to redesign mine again, or else he's not original enough!!!1!!" or rude shits like "our characters look the same, how dare you!!!! I demand that you redesign yours this instant, or even better just scrap that entirely!"