Slip Covers

I don't know if many people have feelings on slip covers or not, but John and I absolutely do...that is, I love them and he hates them. While both opinions are valid... I think there are more pluses to my liking them, than to his disliking them...but that's just me! A few pluses for slipcovers are:

• they are a lot less expensive than buying new furniture
•  you can instantly add color and texture to a room 
• they just look comfortable. 

What are your thoughts? slipcovers are a go or a no?