Personally, I only feel cheated if the set was short and the crowd (no matter the size) was obviously appreciative. Or, if I know the band is doing the encores in other venues but doesn't when I see them and the crowd has been good. Granted, there are exceptions like too many unsolvable tech problems, but that's another issue altogether.
I've found that it's become pretty standard for a lot of Manchester bands not to do encores but to include what would be the encore into their set.
One advantage of an encore is when a band saves their most energetic songs until the end and could benefit from a little breathing, drinking, peeing, and refreshing time. The disadvantage is when the band would like the ending songs showcased but is playing for a smaller or laid back crowd. Doing an encore then is when if feels rather fake.
I did see a show several months ago where when I compared the artist's set list to those in other venues, it seemed that they were smart enough to see that the crowd was lame so just circumvented the encore and just threw it into the end of the set. But, I do know of another city that got a couple extra encores afterwards due to wild audience appreciation. That crowd apparently deserved the extra encores. Just wish that I would have been there for that show instead of the lame-ass yet appreciative DC crowd.
