What is better, foam seating or sprung seating? We have sold both over many years and unfortunately it comes down to one comment….it depends!
Like most things, there is good quality and poorer quality components in lounges and sofas. If you look at a house they may look similar, but the quality of the frame work, or the bricks or the quality of the appliances all add up to big difference in build quality. It is the same for lounges. The most important thing is to understand what you are paying for. By doing your research in regards to frame, cushioning and covers, and comparing prices for a comparable product you can ensure you are not taken advantage of in the open market.
That said, foam or sprung seats? In my experience, we have always had great longevity by supplying sprung seats in our leather lounges. I know from personal experience that the seats will definitely soften over time but don't fully collapse (unless under enormous pressure). Although they do provide a very good life there can be instances, although minimal of a spring “popping” out of its protective layer. This would generally be covered under warranty by most manufacturers if it happens within the warranty period. The most popular springs can be anywhere from 1.3mm to 1.6mm wide.
Foam seating is generally softer than sprung seating. There are many different densities of foam, from a regular seating foam, to a high density foam and even moulded foam (firm). In regards to foam you can choose from many different types, but the retailer normally would have little control over the firmness. What you see is generally what you get. A rule of thumb is if it is soft to sit on initially, it will only get softer, and it may not be long until you are sitting on the frame. If you get a firmer seat cushion, then it will soften over time and hold its shape and resilience for longer. Some retailers have a bit more flexibility over what kind of seating is available. Generally, the less dense the foam (or softer the seat) the cheaper the product.
Most of the time, retailers will just sell a regular seating foam, but there are some that will have some products on range which have a high resilience foam, or something similar like Dunlop Enduro foam which is a great product. These foams are denser and quite often have significant warranty periods to support their product. They also are more expensive.
Bottom line, what is better? Springs are consistently good, but foam can have huge differences in quality. If looking at buying a lounge with foam cushions try and get one with a reasonable warranty to give you peace of mind. Remember, it may look the same on the outside but the inside tells a different story.