I agree that it is not fair to rate them compared to larger sets. That being said, I think it is valuable to add feedback on how it compares to small sets of the same scale.
OK then. for 1993 I guess it was a great small set cause it included DM minifig and shield and most importent 2 crossbows which were relatively weren't widely spread (the first crossbows were out in 1990) so I guess for a small set 2 crossbows were neat.
This set contained a black spear which is again not uncommon part nowadays but then there was only one other Pirate set (6277 - which was a big set) that included it.
The wheels and the black plates are great for bases of carts. The Plate 1 x 2 with Handles http://guide.lugnet.com/partsref/search.cgi?q=3839b
is very usefull if you want to build a sedan chair (it's not an uncommon part tough it's not a very common part in castle).
TLC made again in 1997 almost the same set (6004) with a Fright Knight minifig, this time 2 shields, 2 spears, quiver and 3 crossbow so I guess the new set for weapon inventory is a bit better.
If it was available in cheap cost nowadays I guess I'd buy at least 10 just to enlarge my DM force.
Final grade (as a small set) I guess 7/10.
P.S. Ben, I guess I found what to say about that set after all