Sofas are mainly designed for sitting. A classic bed should be used for daily sleeping. If you often have a guest in the house you need to store somewhere, it's not a matter of thinking about a sofa bed.
At present, the comfort models are equipped with a swinging seat technology, which guarantees an ergonomically correct seating (slight lowering of the seat towards the backrest) and at the same time comfortable straight lying at the layout. If you use sofas for sleeping only exceptionally-a few times a year, you just need to buy a cheaper stretching "classics".
Go for it cleverly
Investing in a sofa is worthwhile even if your dwelling place provides little space and you have problems to save for example seasonal items. It will solve the sofa with a large storage compartment, which perfectly replaces the smaller cabinet or chest of drawers and saves you space in the apartment.