In reply to Kemics:
Just a quick look at the two maps different scales and the same location :-
1;25,000 gives names of roads, names of features ("Mary Magdalene Well, v. 'well')
1,25,000 gives ground vegetation cover much better
More features are named
Better building footprint marked
More accurate scale representation of small objects, such as roads, houses, and footpaths etc., V. 1.50,000 are NOT an exact scale representation of what is there as you wouldn't necessarily be able to see small features if their scale was accurate, as anyone who has compared a map to an aerial photo of the same physical size. (My house appears to be over 90 ft long on the 1.50,000 map, which it isn't!)