I won't drone on for too long about how much I love my sanding equipment. I'm sure you've better things to do. I've got two Mirka sanders for broad areas - the Ceros and Deros, and I've got two Festool sanders - the RO90 for exterior timber work, and my RTS400, mainly for interior woodwork, and for finishing off exterior woodwork. 

These sanders make a MASSIVE difference to my decorating. Sorry for the caps, but I can't emphasise how useful they are. Not only can I sand much quicker with these tools, but attached to my Festool dust extractor, I produce about 5% of the sanding dust compared to sanding by hand - or by machine without dust extraction capabilities. 

Anyway, I said I wouldn't drone on. Suffice to say these sanders are expensive, but worth every penny. They are extremely efficient and effective, and they just keep on going - kind of the Land Rovers of decorating tools. Recently, my RTS400 developed an electrical fault - just a loose cable inlet socket I think. I emailed Festool UK, they sent a courier, fixed it and sent it back. What did I pay? Nothing. They guarantee their tools for 3 years. The service is pretty much impeccable. 

Expensive? Yes. Great value for money? Definitely.