More safety is usually a good idea, except you need to balance it against the extra complexity. A low water cut off needs to be properly installed in a Hydronic system to be effective, so if you do decide on one research the manufactures recommendations completely.
More info: it is generally not needed in most areas (unless by code), after 2014 some more areas will require it, we will most probably provide a unit with our boilers as an option at that time. Some areas do already require it, but to me it is not needed since you will install a 12 psig auto fill valve, there is a prv to prevent over pressure in the event of failure, plus we provide a high limit that shuts the boiler down if over temp occurs, of course that control needs water to work. In my opinion the low water cut off is a holdover from the steam era.