We have a Mitchell Gold sectional in off white duck in our family room. We are a family of five with a dog and while it is not pristine it still looks good. I confess, I think we are going on 18 months and yet to clean the slipcovers. It is a room we tend to congregate in only on weekends, though, as we would tend to go elsewhere to read and there is no TV on schoolnights. YMMV.

It is time though, but it is not at a point where I would feel I must do it before the next party, if you KWIM.

HTH

PS I am a huge fan of offwhite slipcovers. Had a similar sofa in my son's room from when he was a newborn until about age 10. My daughter's nursery had a white linen slipcover chair and ottoman for about five years, and now it is in our MBR.

I have had an off white/ light beige colored slip covered sectional for nearly 4 years.
Taking the slipcovers off to wash is a pain in the behind, and I have to do it at least once every other month, thanks to my 3 kids that seem to always spill things on it. They have some stains that I can't get out, so I'm about ready to order new slipcovers from JC Penneys for them. I did buy a 5 year stain protection plan, so I can replace them free, but now I have to find the paperwork that I put in a safe place. But since I had a newborn when I got them, I can't remember where that safe place is, anyhow I digress.

Don't listen to the liars in blogland, it's a real big pain to take them off, but even bigger pain to get them back on. It's an all day project in my house, and usually a few broken nails. But, I sure am glad I can take them off. I can't believe how dirty they get and I'm happy I can actually get them clean, instead of having a dark sofa that doesn't show dirt, but is dirty.