I am just about to replace my dead Karcher pressure washer. One of the main jobs we use it for is cleaning the drive and patio each year. We have always used just the lance on the highest pressure to do this but some of the new pressure washers I have been looking at come bundled with a patio cleaner attachment. Are these any better at removing algae and stains than just using a lance? No point in spending more if this isn't going to make things any easier.