Very useful.
Moved house a few months ago and now have paved drive with lots of overhanging trees. Despite the time of year they are dropping their leaves on a very regular basis hence the purchase. We looked at various options some of which were very expensive and decided to give it a go - if it didn’t work we hadn’t lost much. They are very easy to attach , my lawnmower has a slight flange but coped with that easily. We did find you need to adjust the height of the lawnmower- so far we have used it for dry leaves on the drive only. It does a good job and collects nearly all the leaves. My lawnmower is about 10 years old so clearly you do not need a recent model for the attachments to work.