According to the typicon, there are liturgies on the eve of Pascha, Theophany, and Nativity, with the other two following after Pascha. They are a kind of "preparation" on the eve of the feast before the vigil and festal liturgy for the day itself and are not really done in the evening. They are an additional liturgy before the feast done on a fasting day of preparation before the vigil. Also, there is a vesperal liturgy for Annunciation if it falls during the week, this is done because it is Lent and it gets weird. But it is written to always be done as such during the week, so nothing is being elided to do it in this manner, it is specifically designed that way. There is a vast difference between the way this is done and the way other faux-vesperal liturgies are done. Namely, they remove all the aposticha and litiya material, all the matins materials, and remove the festal antiphons of the liturgy (those are important). They also really muck up the whole "liturgy of time", since services are put at points of time during the day for a reason. And, personally, I really can't do an appropriate fast for evening services on days I work. I'd prefer vigil or just vespers, frankly. A parish I was at used to have 6:30 am weekday liturgies, every Thursday and feastdays. I was regularly there on the Thursdays until I wasn't able to do so anymore. They had a reasonable attendance. I realize that's not a solution for everyone, but it is a thought. Bishop Tikhon has an article about them. But, as always, follow your bishop, we aren't qualified to have opinions.
HTC: Evening Divine Liturgies