Looks like they nosy through your post before they scan it. I wouldn't want that.
I had a PO Box for a few years, but it was certainly not worth the price increase to £200+
I had the box and forwarding to my home address and to be honest it was not reliable at all. Sometimes mail would arrive to me a month later, for 6 months some mail was left in the box. It got to the stage where I kept going to the local sorting office to make sure they had left no mail rendering the forwarding service I had used redundant.
I complained to Royal Mail and to the local sorting office and they refused a refund because I had not complained multiple times (my complaints were not in their records).
When I cancelled it I was still invoiced.
Overall very poor experience and a waste of money, I'd seek other options unless you're talking about lots of regular mail whereby they can't forget about you.
Thanks for your reply Alex, what do you use now?
PO Boxes aren't a privacy solution because anyone can write to Royal Mail and ask for the real address of the PO Box holder and they will provide it if a genuine reason is presented. Visit this link and look under "disclosure of information". I suppose the service could be useful if the operator wishes to collect their mail rather than have it delivered to a destination (known as PO Box Collect, £170p/a).