Several months ago I was temped by the excellent price of Piccadilly notebooks compared to the price of Moleskine (the first notebook I became interested in). I picked up a few and I was originally impressed by how well they performed. There were some obvious differences, but given the large price difference, I didn't think they were deal-killers.
After using a pocket sized Piccadilly for several months, I've decided that it won't replace Moleskine for me anytime soon. I think Piccadilly makes a good product and is definitely a good value if you are watching your budget. For me, though, it is just too far from what I love about Moleskine. The paper is rougher and stiffer, the cover material is not as smooth and supple, and the binding does not loosen to allow the notebook to open fully flat.
One of the first things to attracted me to Moleskine was that it is a luxurious product-- one of the finest notebooks you can buy. But even though it is very high quality, it is relatively inexpensive. At $12, it is certainly more expensive than other other notebooks, but I can afford to splurge on a $12 notebook. If I were going to "splurge" on the best car on the market, I could easily spend $100,000.
I recommend Piccadilly if you are on a budget, but I am sticking with Moleskine for now.