Based on your post, it sounds like the style of sofa you have now is an Easy Bed (also known as a J-Lounge) sofa. These options are RV friendly and come in a variety of different styles to suit the layout of your coach. The backrest of the sofa lays flat at the same level as the seat cushion to create a bed. The seam or joint between the seat cushions creates that low spot you refer to. If you like storage under the sofa - this is the best option, but as you mentioned, it can be rather uncomfortable. It's a bit of a trade-off unfortunately. A more comfortable sofa bed option is Flexsteel's Magic Bed. The Magic Bed's sofa cushions flip practically inside out when the chair is opened toward the center of the coach. When doing so, a large cushion at the same level in height spreads across a full-size bed surface. Unlike a Sofa Convertible (aka - sofa with pull out bed), it's a very comfortable sleep in a confined space. The Sofa Convertibles, typically offered with a coiled spring mattress of low quality, is also available with an inflatable air mattress option. We get calls on a regular basis throughout the country by those who have this style of sofa bed and the air mattress bladder has popped when the bed is folded back under the sofa - so buyer beware!