Many fans who have read the Infinity Arc in the manga still love the S anime, but think the manga is “better.” True, I think some elements are better portrayed in the manga than in the anime, but some elements, such as characterization, are better portrayed in the anime. That said, here is my overall impression;
Chibiusa and Hotaru’s friendship has much better development in the anime. We get to see and experience their blossoming friendship. Literally every episode after Hotaru’s introduction in episode 112 is either dedicated to them or has scenes that portray their dedication to one another. From Hotaru overexerting herself to chase after Chibiusa, to Hotaru going on a picnic with Chibiusa and her future parents, to Chibiusa defending Hotaru’s innocence time and time again, to them playing cards together…. it feels so rich and realistic. These are two young girls who have blossomed in their friendship. I can go on and on.
But, in my own opinion, the manga didn’t develop this relationship nearly as well as in the anime. We go from their meeting, to jumping to Chibiusa visiting Hotaru’s house a few acts later, to Chibiusa discovering Hotaru is part cyborg. The only real bit of friendliness we see is Hotaru inviting Chibiusa and her friends to a movie, and that was a flashback. It doesn’t feel forced at all, it just feels… not as real. The only really touching scene we get is when Hotaru returns Chibiusa’s Ginzuishou back to her and they have a very heartfelt moment. Their friendship is much sweeter and funner LATER on in the manga, after Hotaru is reborn.
So, all in all, I personally like Hotaru and Chibiusa’s relationship development better in the anime. It’s just my own opinion.

I think this is an example of "filler" in the anime being an advantage. The S season was particularly good at having episodes which, even if they did not introduce terribly new plot elements, would advance characterization. As you mention, there are about seven episodes (112- displaying the evolving friendship of Chibiusa and Hotaru. In the manga, I assume Takeuchi had to keep the plot moving relatively quickly given the limited space, so she couldn't dedicate significant screen time to their relationship.

I agree -- I think the only good thing about anime in general is that it usually throws in filler episodes. For the Sailor Moon manga especially, the plot is the driving force of the story line and I feel that it is the one weakness of the manga. In the anime, you get to know the characters a bit better and see relationships within the endless array of added episodes to the series as a whole.

Naoko was nice to enough to include a few extra stories of Chibi Usa's adventures though. However, I am not a Chibi Usa fan so it did not matter to me too much. XD However, I do like the friendship between Chibi Usa and Hotaru in the anime very much.

Sailor Jupiter wrote:

Naoko was nice to enough to include a few extra stories of Chibi Usa's adventures though. However, I am not a Chibi Usa fan so it did not matter to me too much. XD However, I do like the friendship between Chibi Usa and Hotaru in the anime very much.

I loved that random extra with Chibi Usa's friends Naruru and Luluna, where Hotaru is being all "I AM Chibi Usa's best friend, YES ME." over them. Though the rest is pure crack, this part was so cute. <3

Sailor Night wrote:

I loved that random extra with Chibi Usa's friends Naruru and Luluna, where Hotaru is being all "I AM Chibi Usa's best friend, YES ME." over them. Though the rest is pure crack, this part was so cute. <3

Yes, I loved that! It was so adorable. As Sailor Saturn, she is very mature and serious. But in reality, she is still a little girl! It's nice to see the childish side of her as well. ^^

I think it`s because the anime wanted to focus on that, in the manga their friendship is not that important. And though in the anime it`s more heartwarming, I think it`s more realistic in the manga. Hotaru was a very dark person, and she became all cute and fuzzy after S. Chibiusa tried her best to be friends with her but it was hard, while in the anime both girls were too much alike imo and became BFFs quite quickly. in the manga they WANTED to be friend but couldn`t.

I am actually finishing S right, while reading the manga haha

I must agree that I did like the development of Chibiusa and Hotaru more in the anime than in the manga. The manga made it seem not that important where as in the anime, is really based much of the 'S' season on it as it was hinted that Chibiusa was probably one of the reasons why Hotaru awoke as Sailor Saturn in order to defeat Mistress 9.