To a degree I definitely think there's objectivity to this debate about charge shot indicators. I agree that having the indicators on or around the player model with color coding is quicker to notice then an indicator at the top corner of the screen. I think that statement would be fairly easy to prove in a study as well, particularly with eye tracking and measuring response times.
That being said... I also think there's a lot of subjectivity involved. You can form statements about certain features being more efficient, and prove them with studies... but does it improve the experience? I think that question is much harder to debate.
A good example is Balrog. I definitely believe that merging it's movesets into one mode would make for easier combos (I think most of us can agree on that), but I'm not sure how many of us would want that change. I talked to a friend who believed that the 2-mode design gave it a unique personality from all the other weapons, which improved the experience for them. It's a completely valid opinion to have, and it's difficult to make arguments when experiences are factored in.
Most importantly, there are no studies directly proving anything, so it's difficult to say anything is truly an objective fact. You can pull from related studies that support your argument, but... Ultimately it's still best to treat it as a theory, to create a more friendly and inviting atmosphere. I can get fairly adamant about my design theories as well, and I fail at this too on occasion. Food for thought though, I think forums are a great place to practice these communication skills.
