I visited Vigan just two weeks ago. My memory and impressions are overall indeed tilted to the positive side. I found it hard to articulate succinctly. Let me just give one point.
In terms of showing information relevant to the visitor clearly, Vigan probably does a marvellous task in one stroke, not often found in Asian towns of Vigan's size. The map produced by the city government is very understandable, helpful, nice looking, convenient. You don't even have to get a paper copy. At the intersection of Crisologo and Liberation there is a very clear map on a wall. Always get back to this intersection and you will find your way in Vigan.