As Facewest claims, these are probably the best screws on the market - simple but effective design, handle with minimal bulk (compared to some of the competition - the small size of the handle could cause some problems if used with bulky gloves or mittens). Color codes are great for fast sorting on the harness.
I purchased the 19cm screw for use on glacier travel and crevasse rescue, it's light, sharp and goes extremely easily into hard compact ice. The little flip up handle is a bonus for when you want that extra umph to get it in but doesn't really affect the weight at all. I still carry mine with the original protectors that come with the screw, hopefully saving me money in the longer term.
I've got a full rack of these and find them outstanding. I won't use any other screw, so always insist to my climbing partners we use my rack of BD screws if they have the misfortune to have invested in a different brand. They bite quickly and easily into the hardest Alpine ice and once they have bitten, simply flip up the nob (no problem in mountaineering gloves) crank them in, clip in your draw and stop shaking! Worth using the little safety caps to keep them sharp and prevent snagging in your pack. The safety sleeve to protect the threads is useful too. Also a great feature is how well the screws rack on your harness. They rack in a really compact way and you can arrange them to point backwards on your harness. Ice climbing is faffy and scary enough as it is and this feature is one of the main reasons they are so popular. With the recent refinements of making the nob colour coded and slightly conical (for better grip) amd the addition of the extra clip-in point on the hanger it is hard to see what BD could do to make this screw any better.
The best in the world? maybe, but not definitely. Positives to these are; 1) biting straight away in hardish ice. 2) the coloured handles so you can instantly see what size you have when you have the inevitable pump/fear that necessitates the placing of a screw. 3) the clip hole is a good shape and size and sits well, meaning you don't faff and waste energy getting the quickdraw in. All in all these have no real faults, you can even sharpen them yourself and it tells you how to do it on the BD site! Only negative is as a comparison, the Grivel 360 is better in bullet hard ice, but only because you can torque it more with the longer handle.
I've used different types of ice screws during my 15 years of climbing and the Black Diamond Express Ice Screws has by far the best product design there is. Compared to the second best option (Grivel 360) these have one very big advantage. They rack smaller in the harness. You can rack five of these in one ice clipper or carabiner. The Grivels you can have two in each biner. It makes a big difference if you have full rack of 10-12 screws. Both options bite ice well and placing them with one hand is no problem but for the racking reasons I can recommend only these. All in all it's a very good product. Don't be put off by the price, they are worth it.
Easy to use, rack very nice, and works on all types of ice. I use a combination of grivel 360 and BD express and that is a perfect set-up. If I should use only one type of screw, I would go for the BD express due to its easy racking and functional properties.
Black Diamond Express screws in my opinion are the best on the market. They rack the best, come in colors, sink really well into the ice, have two clip-in points, and are the easiest to screw in.
I carry a Black Diamond ice screw for occasional protection and emergency anchor. They are very quick and easy to install and in my experience utterly reliable. Mine held a big fall on steep ice recently without incident. I keep the plastic trellis in place to protect my other gear from the threads, but I recommend taping up any ragged ends on the trellis; it's quite aggressive to tape slings hanging nearby.
Black Diamond often let the products speak for themselves. The all highest quality and a very good design makes you really feel you can trust these ice screws. This is the easiest and best screws I have used. They are compact and hangs nicely on the harness. They are easy to handle even with gloves. They are very quick to put in place. I can not find anything negative to say about these and would recommend they strongly.
Caveat - Only used this for crevasse rescue and not ice or even mixed climbing. My initial observations are as follows:Pros:Relatively light and very intuitive 'feel' which gives real confidence in its placement, especially if under pressure. V well made with effective teeth for initial placement and entry and a smooth action given the collapsible handle. Cons:None that I have come across, although they are on the pricey side, but then when it comes to protection I would always pay for the best, wouldn't you?Probably go for the longest length possible for crevasse rescue for that extra assurance.