I had a moderate-mild loss (my loss is reverse slope, meaning the greatest loss is in the lower tones) when I was in college.  That is when I got my first hearing aid.  I am also sensitive to certain sounds.  My newest aids had a feature that I had to have turned off, it drove me nuts.  Basically, if it didn't register any speech sounds or other loud sounds it would go into a sort of "sleep" mode.  Then when sounds it thought were important came in it would build back up in volume.  It was really annoying.  The day after I got the aids we went to the creek.  The kids went exploring with my husband and I was sitting enjoying the peace and quiet.  Then I noticed that I could no longer hear the babbling creek.  But when one of the kids shouted hi to me, the babbling sound of the creek came back.  It was really driving me nuts.

I do hate certain environmental sounds, but you actually learn to tune those small things out like hearing people do.  The ticking clock doesn't seem to bother me as much as it did when I first got my aids. 

Basically, the benefits of having a hearing aid definitely outweigh the negative aspects.  Yes, you will still have difficulty in noisy crowds, but many aids have noise reduction features or directional microphones to help with this.  Also, there are many assistive devices that help with this also.  Harris Communications has many of these devices (things like the "Pocket Talker").  They can get expensive, but if you need them frequently they are well worth the cost. 

I honestly miss the days when my hearing loss was only moderate.  I now have a profound-severe loss in my right ear with no speech recognition and a severe-moderate loss in my left ear. 

Good luck with the decision.