It guarantees you won't "lose that investment". Whether or not it is stolen is a different matter. Also there are angle grinder resistant locks. Check out videos of people testing them out and buy ones that they fail to cut, if your primary concern is not having it stolen (rather than losing your investment). Good ones seem to be around $300.
Angle grinder wins against any lock. Maybe you're not the easiest bike to steal by having your very expensive lock, but in certain areas (NYC being a big one) that basically doesn't matter. And insurance claims from the bike locks still suck, since you have to deal a lost bike and an insurance claim every time that happens...
Yes. My time spent in Manhattan made it clear you basically never leave a bike locked up there. There’s a reason why Kryptonite will only warranty its most expensive lock (and none of the cheaper ones) in Manhattan. The other boroughs they warranty cheaper locks, but not in Manhattan.
