I had been looking for a lock that has a mount to attach to my bike, since I don't fancy carrying a heavy lock in my backpack all the time.
Several other locks with mounts that use clamps or other mechanisms simply couldn't mount to my old secondhand bike because the part of the bike frame it needs to mount to has too big a diameter for the mechanism to wrap around. This one did it with no issue. I don't need the mount to be secure against destructive attacks, so this meets my requirements perfectly.
I also picked this lock over others for two reasons: 1. Bike locks can be easily defeated using bolt cutters, taking less than a second. This lock's shackle has an 18 mm diameter, make it difficult for most bolt cutters. Thieves generally prefer smaller bolt cutters they can conceal, so this lock should be safe against this quickest attack method. Do note that other locks with similar shackles, but whose thickness includes a PVC or silicone protective layer, will not provide the same level of protection (this includes other locks from this same company). 2. Bike locks can also be nondestructively defeated by picking. This lock uses a disc detainer core. It has very few discs and I doubt it has any security discs, so it isn't very secure for a disc detainer core, but disc detainer cores require specialized tools to defeat in the first place. Very few thieves will carry the tools nor have the skills to defeat this lock nondestructively.
The added cable is an additional security measure to prevent people from stealing your wheels. The shackle should be locked to your frame and if possible one of the wheels. The cable provides far, far lower security because nearly all chains can be defeated near instantly by a medium sized bolt cutter. This chain is pretty thick, however, as other chains from other comparable locks I've seen are barely 50% metal by diameter, with soft coating accounting for the rest. This chain is more like 75% metal by diameter, so small bolt cutters may have issues.
This lock is still weak to two types of attacks: 1. Prying it open - with sufficient leverage force nearly every lock can be pried open, the bigger the lock (as in the area under the U, where a pry bar would be inserted), the easier it is to gain the necessary leverage. This is a bigger lock, so it is vulnerable, but also, the shackle is thick enough that it would require significant strength to pry this lock open. A thief with a pry bar faced with a rack of bikes locked by various locks would probably attempt to pry this lock last - it would be doable, but not easy. 2. Handheld angle grinders are the kryptonite to bike locks, even Kryptonite-brand bike locks. Very, very few locks using specialized materials are resistant to handheld angle grinders, all costing about as much as an average bike, so unless you are locking a very expensive bike, I think it is not worth considering any truly angle grinder resistant locks. Most others locks, including this one, can be defeated very quickly. However, this attack is loud and easy to spot, so it isn't likely to be used where there are people nearby. I'd say given the thickness of this shackle, this lock would last 5-10 seconds longer than competitors, and that is enough for me.
Given the above safety analysis, I think this lock is good value for the price range it is in. Always remember that locks only keep out people who aren't determined, skilled, or well-armed. How determined, skilled, and well-armed a thief stealing your bike will be should be estimated taking into account the value of your bike, the locations where you lock your bike, and the time of day/duration that you will leave your bike there. Get a bike lock that is sufficient to protect your bike in the circumstances you will need it.