Jennifer's favourite mitzvah is mikveh, as you saw in her posting today. She sees it as spiritual. I always refer my female conversion students to her to talk about it. I can tell you how to build one. I have never been able to get into the spiritual side of it.
Before I comment on my personal feelings, I need to be the Rabbi. Given that the mikveh is essentially a secret sorority, it should be many things. Above and beyond the questions of spiritual health, it should also be a place of physical health. As such, the dressing rooms should have posters with proper instructions for a monthly breast exam. There should be phone numbers for shelters and abuse counseling.
On a macro level, mikveh attendants should meet once a month in cities where there are multiple mikvaot. They should discuss different procedures for helping someone with physical challenges in and out of the mikveh. They should discuss Mrs. Schwartz, who goes to a different mikveh every night. They should learn to ask the simple question of whether it is the right night to be there. Being forced to go to mikveh early is prevalent in abusive relationships. By the way, there is a different method of counting the days of menstruation amongst the Sephardim as opposed to the Ashkenazim. A question to the mikveh attendant about that counting might be a question about personal custom. It might also be a sign of a much deeper marital problem.
On a personal level, mikveh for me is very erotic. In the week prior, I am already thinking about 'mikveh night.' I plan the evening. I shower also. I put the kids to bed as early as I can get away with.
One of my teachers pointed out that if the point of mikveh is for the monthly honeymoon that Jennifer mentioned, men should go too. It is not only incumbent on the women to maintain the romance in a relationship. I should go monthly. I do not. I will start at some point.