How to handle Co-author who is not listening the suggestions to improve the paper quality Assume I am involved with a work and the lead author is writing a paper. However, after every draft version, I see that not all my comments are well addressed in the revised version. I expect that if the comments or major suggestions are not addressed, then some explanation must be given.  During the previous conversation, the coauthor did not raise any doubts or concerns about my suggestions. Thus I pointed out these issues in the paper again and they again fell on deaf ears  this loop continues. 


As I already spent a huge amount of time on this paper and made a significant contribution, I don't want to withdraw my coauthorship. 
Topic is relatively new, in addition the current version is good enough to have a decent chance of getting accepted into a medium level conference. 
Some minor issues (may be major) are bother me. I am not sure whether I am wrong. However, there is no discussion on on my concerns even after they are explicitly highlighted. 


Should I just let the paper go? or make some statement? I don't want to burn bridges with any of my coauthors.
In every scientific paper that I have been involved in, there has been opportunity for co-authors to directly edit the manuscript themselves, if they wish to make a contribution.  If you feel that you have suggestions that are not being taken up, I would advise you to ask something like:


  Would you mind if I did a pass on the paper to edit in some of the suggestions I've made?


If your co-author hasn't been editing in your suggestions because they are unclear, overloaded, or not able to do so, this will give you a chance to adjust the paper in the ways that you want.  If, on the other hand, they actually disagree with your suggestions, then they may not want you to edit them in, and you can then actually have a discussion about whether and why the proposed edits should occur.

In short: I believe that you need to shift from being a passive critic to being an active contributor who provides actual text that accomplishes what you want to have accomplished.