It was a really tough call for us between the 23SS and the 23IKSS. They both have great storage and sleep the same number of people. In the end, the layout was the deciding factor for us. We chose the IKSS with the airbed option after imagining what it would be like to stuck inside on a rainy day with three kids. We pick it up in ten days.
Both the dinette and the sofa are directly across from the entertainment center and out of the way of whoever is working in the kitchen. The DH and the kids can play games, watch movies, etc. and be safely away from the kitchen - important for us with a two year old but nice for anyone! We felt that this outweighed having to put one of the slides out for access while traveling. We probably won't do that very often anyway.
I suspect that you will be happy with either one - they both look like great HTTs. Good luck and have fun!