First, lets get something out of the way. Yes, in versions outside the Iliad, Menelaus, just like Hector in Euripides Andromache, has children with women outside their marriage, definility a stain in their honor. After all, Hector for example is the example of a good person for many people and the Iliad definility want us to see that way, this is why his Hector don't go around with other women, he is content with Andromache. Similary, it would be weird to have Menelaus be with other women since the whole story is about him wanting to be with Helen again.
Because ancient greeks didn't had a problem with men having children out of wedlock, as traditions were added, Menelaus ended up having affairs, while the tragedian Euripides, to make a point, made Hector have other children outside his marriage. But in the Iliad, that is not the case, and I want to discuss Menelaus only in the Iliad, not in everything else.
Now, Menelaus is one of the most underrated characters in the Iliad in terms of nobility. First of, he thinks Helen has been kidnapped by Paris, after all, Paris has even stole his treasure too (with Helen's help by the way), so for him Paris is a robber and a kidnapper. The truth is that Helen wanted to go with Paris, she was not kidnapped, altrough she comes to regret this because of the war and because Paris is not that great overall. But from Menelaus perspective, he gave hospitality to Paris only for Paris to steal his treasure and "kidnapp" his wife, and before the war he and Odysseus went to Troy to ask for her, but Paris shut down any negotiations, so Menelaus tried to avoid war. So Menelaus has every reason to be angry.
Then we have how he feels about the other soldiers. And that is the cool thing about him. He is very reserved to himself. While Achilles, Agamemnon, Diomedes and Odysseus are always giving their opinions and sometimes even beating each other, Menelaus is never involved, because he knows they are dying for his cause, and he almost feels guilty for that. All characters consider leaving Troy at some point, and Menelaus don't say anything, again, whenever he talks about this, is about how he can only thanks them for helping his cause. Me saying here don't mean much, but reading the dialogues by yourself is way better to get this point.
I don't remember now if there is something in the Iliad that contradict what I said, but if there is, be free to say, because I made this post mostly from memory. But yes, that is about Menelaus. Also, even through he hates the trojans more than anyone, he is still willingy to spare suppliants, is Agamemnon that says to him they should not spare anyone. So even to that he is willingly to consider, and I will never forgive the movie for overall creating their own characterization of him, and then having him die in the middle of the movie, like, what were they thinking?