I had the older verison of Disk Doctor, and I didn't mind at all paying for this newer version. This is why… I have had the same basic image that I have transitioned through all of my Macs, spanning back to the first Leopard release of the OS many years ago. I’m fairly tech-savvy and good at managing space, but as you can imagine…I’d allotted a lot of ‘hidden’ files and applications over time that I have no need for — but weren’ta ble to track down. Some I had forgotten about, some I wouldn’t have bena ble to know about. I first did a TIME MACHINE BACKUP, like the Disk Doctor Pro people recommend — and then I safely went from ~4GB fo space earlier in the day to now having 100GB! Disk Doctor Pro saved me more space than even its clean, as it gave me a ‘hint’ on where to look for other bulky files, based on the ones it recommended for deletion. Long story short — this app paid for itself many times over within minutes. Even if you are a good ‘space manager’, this is an app really worth having and will pay for itself…if not today, then a bit down the road.