I will start off by saying I am a big fan of Italian hand stained leather. It is a stiffer leather with a shiny sheen to it. This is comparable to Bosca's Old Leather. If you like soft nappa and hate stiff shiny leather then this is not the wallet for you. You will gripe about it. If you like Italian leather though you will love it. I noticed some people who don't like Italian leather complaining about Castello Italian leather products simply because they didn't read carefully and thus didn't understand they were getting an Italian leather product. Intrinsic to an Italian leather product is that it is easily scratched. That is the nature of the beast. Mine came with some minor scratches already. I had hoped it would start out with none but there were some minor ones. Minor enough that I will not consider exchanging it. You definitely should not carry anything metal in the same pocket like a money clip or pen, if you do then it will be scratched up. The only thing safe to carry in the same pocket is loose paper or cash.
I have been using one piece (as opposed to the ones that fold in half) slim card holders for many years now. I have used them from Bosca, Tumi, Coach and Fossil among others. My current holder is a Fossil one.
This Castello card holder is the same height but 1/4 inches longer than my Fossil. I prefer as small as poossible but the 1/4 inch is no big deal and in fact as I will explain shortly is better. The true dimensions of mine is 4.25" long by 2.75" wide even though the Great Offer Stock description states 4 inches long. It is small enough to fit comfortably in a front pants pocket, shirt pocket or breast jacket pocket.
Many slim card holders have an outside plastic ID window, this one doesn't have one. It looks nicer all leather than with one side being plastic. This means you will have to keep your license in one of the card slots. Since almost everyone who you need to show ID to wants your ID removed and will not read it through a plastic window, it means a plastic ID window is not needed anyway.
Out of all the non-folding slim card holders I have seen this is the only one that has more than 5 slots. From Coach to Fossil they only have 5 slots counting the middle pocket. Some have even fewer like the Bosca weekend wallet which has only 4 slots.
My current card holder is configured as follows: plastic ID window and card slot on one side, 2 card slots on the other and center pocket. I have my license and credit card on one side, 2 credit cards on the other side and 2 more credit cards plus a book of stamps in the middle pocket.
The new Castello card holder has 3 exterior card slots on one side, 2 exterior card slots on the other, a fabric card slot inside each wing and a middle pocket. Thus in total there are 7 card slots, a central pocket plus more room in the two wings for money or receipts. By far this has the most room of any on the market that I have seen.
While the wings can hold cash, naturally sticking a wad of cash in them will make them stick out. I normally keep my cash folded in half (no money clip) in my pocket right next to the slim card holder. The central pocket though on the Castello one is large enough to fit my cash comfortably (11 bills folded in half). The 4 1/4 length means the cash will fit comfortably and be easy to stick in and pull out. Since the entire central pocket is free (as I mentioned everything I now carry fit in all the card slots with one slot to spare) I'm still deciding whether to keep my cash in it or stick new items I didn't used to carry in my old less roomy one like business cards for instance.
My only real gripe in terms of the design is the wings. I would have preferred that the sides were longer and sewn down. That would give it more utility and make it less bulky. Things can fall out of the wings if turned down so are not as useful as they would be if sewn down. As I already mentioned there is a fabric slot to hold a card in the wing so that won't fall out but whatever is in the wing itself can. Inside a pocket it is no big deal but when you take it out it can be a hassle, enough of a hassle to not bother using the wing so it might as well be a normal sewn down pocket. I also wonder why they didn't make both sides the same so there would be 3 exterior slots on both sides instead of 2 on one side. There is plenty of room already but it would not have hurt to add the extra slot. These are the only things design wise that I would like to see changed.
There are few Italian leather card holders out there let alone at this price, and no (non-folding) card holders period that offer as much room. As I said it is the only one I have seen with more than 5 slots counting the middle pocket. Counting the middle pocket and wings this has 10- double. All in all this is a nice piece at a good price.