I bought the Ikea corner sofa in 2003, with 2 sets of slipcovers. The sofa itself held up pretty well but lost a "leg" when it was about 5 years old. The slipcover fabric was nice and sturdy but they use something that looks like interfacing on the main slipcover under the cushions where it doesn't show. That "fabric" doesn't hold up to heat and when my iron accidentally touched it, it melted. I also made the mistake of putting the slipcovers in the dryer and they shrunk, then when I stretched them onto the cushions, 2 of the zippers broke. That said, I love Ikea and love their styling. They have a nice choice of fabrics for their slipcovers and if you buy a popular piece, you should be able to find replacement slipcovers for the sofa in the future.
I also bought a sofa and 2 matching chairs from Lands End at the same time. They were more expensive than the Ikea sofa and were also slipcovered since I have 4 kids and a cat. These slipcovers are of better quality fabric, the foam on the cushions is more firm and the sofa itself is holding up better and will probably be worth re-upolstering when the time comes. However, my cat clawed the slipcovers and they look tacky. And Lands End no longer sells these pieces so I'll have to buy new custom slipcovers or upholstery, and it will probably end up costing as much as it would to just replace them with new furniture from Ikea.
So if you have kids and pets, it might be worth it to spend less and get an Ikea sofa that will serve you well for now, and that can be replaced when it looks bad.