We spent one night at Seashell during our Key West trip. The location was good, but the room we had didn't meet our expectations. It wasn't anything special, as it felt damp and humid, although it was nice that it had a refrigerator.
We were not happy with the big, loud AC placed next to the bed, which had to be turned on unless you want to wake up in the middle of the night in sweat. Either way, we had a most of our sleep ruined since the fan from the AC made such loud noises.
The worst part was that there was a cockroach in the shower. Before we were calling it a night, my girlfriend screamed as she took a shower and, lo and behold, a big cockroach was on the shower curtain. I had to squash it and look for more cockroaches before we were able to go to sleep, disgusted. As we checked out the next morning, the lady in the hotel lobby asked if our stay was good. As I handed over our room key I told her that it was not what we expected and we had a cockroach in our room. Her reply was "thanks", as she walked away. We stood there for a good minute just to see if she was coming back, she didn't.
All I can say is, if you are looking for cheaper accommodations (although we paid $300 for this room AND had a cockroach in our room) in Key West, find something else. This was by far the worst accommodation we had during our two-week stay in Florida.