I've looked at these tools over the years and have never bothered to use them, because a straight read of the notams from the NATS site is pretty fast (using the Narrow Route Briefing).
The vast majority of the stuff that comes up is irrelevant rubbish... baloons flying below 400ft, some survey aircraft flying "somewhere" within a polygon marked by a list of coordinates (as if such an aircraft could not be found absolutely anywhere anyway), a military formation flight somewhere (as if such an aircraft could not be found absolutely anywhere anyway), etc. What really matters is stuff like prohibited areas, out of action navaids, closed airports, etc. The rest is garbage.
Plotting notams has always been plagued with problems like what to do with a duff VOR whose circle of relevance is something huge like 200nm. Yet, that VOR being O/S might be relevant to a pilot navigating using radio nav.
I've found that the only notams which take any time to work out are the prohibited areas specified as a coordinate list. The summer airshows tend to be listed like that and for that a graphical facility would be great.