I've only had experience with air suspension but I've read a lot of forums and 50% say go for coil springs and the other 50% say stay with air suspension. It depends on what you use it for I guess. Some say coils make vehicle sway on corners and it's rough ride - others say it's the best thing they've ever done. All i know is that I spent 470 pounds last week on a height sensor switch, a new air pump and the fitting costs and the rides brilliant again. On the other hand, that money could've paid to have it converted to coils with no further suspension break downs but I needed the car on the road that day so Ihad little choice.