Merkur 34c

Pretty new to wet shaving and outside of the Merkur 34c I don't know how anything else shaves and I was wondering what you would consider this razor? Aggressive, mild or relaxed? I've noticed that no matter how I go about shaving the bottom of my neck I always get red irritation that does clear up but it takes a few hours, and was wondering if I may need to get A more aggressive razor or a more relaxed razor or if it is just human error? I have also tried a-lot of different blades, and they all leave the same irritation.

Thanks!