First of all, a sharpener who's name has been floating around as one of the best- KUM automatic long point.
The German-made KUM sharpener features a 2-hole sharpening system; one for sharpening the wood and the other to sharpen the lead to a long point. It has an automatic brake which will stop sharpening once it has reached the optimum length. Whilst I got a decent enough point from the first hole, when trying the second I found it made no difference at all. I tried changing the blade (you are given 2 spares) but it was the same result. From reviews online, this is something that only happens to the minority of users, because generally this sharpener is highly regarded. As you can see, there's not much of a difference at all apart from the wood looks rougher, as if a layer has been taken off the top. Whilst I can't personally vouch for this sharpener with my experience of it, the overwhelmingly positive reviews online tell me that I've probably got a defective product with blunted blades. I'd love to hear your thoughts if you own this.
EDIT: I decided to give the KUM sharpener one last try with the second spare blade and guess what? Super long sharp points! I've heard a lot about dull blades straight off the production line with this brand, so if you have one of these I would definitely test all your blades and contact KUM if they're blunt.
DUX is another German company who have specialised in making exceptional quality sharpeners for over 100 years. This adjustable sharpener is made from solid brass and presented in a leather case, giving it a professional and expensive feel. By twisting the knurl at the end, the blade's grip on the pencil is tightened or loosened, producing 3 different tip lengths from blunted to fine. All 3 settings produce a similar length, but the third is particularly sharp. It's when you look at the length of the pencil that you see the difference in how much you've actually taken off.
Made by the same duo of companies, these next two sharpeners are wonderful- yet there's still one that outperforms the other. The K'ZOOL has 5 different point settings from short to long, the rotatable wheel changing the angle of the blade to vary the lead length. There's also a handy button at the centre which will eject any stuck leads from the blade area, and a removable hatch for you to empty the sharpenings.
It produces the most noticeable contrast in the pencils, with the number 1 setting exhibiting minimal wood loss and a short, sharp point. This ability to retain as much pencil as possible whilst still having a needle sharp point is what will end up saving your pencils and making them last as long as they possibly can. I'll be sharpening all my pencils on setting 1 or 2 with the T'GAAL- just look at the difference in length loss across the board!
Here are links to all the sharpeners I've reviewed today along with their prices as of 10/10/15. Free delivery on all orders over £10, just £1.50 shipping on anything else.
Kum Automatic Long Point Sharpener AS2, £2.,79
Dux Adjustable Brass Pencil Sharpener, £13.99
Kutsuwa Stad KZool Pencil Sharpener, £2.50
Kutsuwa Stad T'Gaal Adjustable Pencil Sharpener, £6.98
I was given these products in exchange for an honest review.