Having recently (finally) acquired 6086, I was inspired to re-build my old 6081 with the help of Peeron (the actual instructions having been lost long ago).
This was my first - and, indeed, for my entire youth, only - large castle. It has its ups and downs.
On the plus side, it has a keep or keep-like structure; many "Golden Age" LEGO castles omit this entirely, with the only large structural edifice being the gatehouse. In the same vein, the keep is taller than the gatehouse. While 6086 and 6074 do have a secondary structure that could be construed as the keep, they are dwarfed by the gatehouses.
On the downside, the usual short LEGO battlements of 1.6-2.0 studs in height. The wall around the courtyard is far too low - even as a child I was irritated by this, and remember complaining to my father that the 'bad guys' could just step over the wall - and the jail is an eyesore.
Nevertheless, as another pointed out, it has a certain ... 'character'. And I love the lower level of the keep tower, with the tall, arched cobblestone gallery ... that part always catches my imagination. I envision the king and the princess strolling along, admiring the landscape, as golden rays from the setting sun stream between the pillars. Overall a win, even if it doesn't utilize the baseplate to the same extent as the larger 6086.