The Crab 6 and crampons of its ilk are really designed for flat icy terrain, and are probably most often employed for glacier travel, or for industrial use (people working on flat icy ground). AS soon as your boots start to bend (imagine walking up a 20 degree slope) you begin to loose contact between the crampons and the ice/snow. If you’ve got the most flexible ankles in the world, then you may manage, but for most having points on the forefoot is vital for traction. So unless the mountain you plan to climb has zero elevation, then go for something that can tackle steeper walking on snow and ice, like the Petzl Arvis, which is still light (810g) and has ten points. The problem with crampons like the Crab 6 is that you’re buying it for a set of climbs and conditions you know very little about. Perhaps you don’t need crampons, and could romp to the top in just your boots, then then perhaps you’ll find a section of ice just like that which killed so many on Snowdon a few years ago. How do you know that you’ll always be on the track (I know people who’ve had to go and carry out rescues on Toubkal, and they had no idea what type of ground they’d find).
For winter walking and climbing your crampons (along with your axe) are critical to safe mountain travel, and so although you can go for lighter models (you could look at alloy crampons), it’s worth saving money and weight elsewhere.