I was asked recently by one Ryan Ellis via Twitter what I thought about a recited communal Vespers from a practical standpoint. It's a very fair question, and one deserving a better response than can be contained in 140 characters.
First, the obvious thing to say is that it is much easier to teach a group to recite Vespers in common than it is to teach them to sing Vespers in common. If we were to compare this to the Mass, it is much easier to have a Mass fully recited than one which is even partially sung. In the barest sense of the word "practical," it is more practical to recite Vespers in common.
However, aside from the merely aesthetic reasons for having a sung Vespers, we might consider its effect upon a congregation. Consider your average daily Mass, for instance: it's a Low Mass in English. Very few people show up. Granted, a lot of people won't come to a daily Mass because of their work or school schedule conflicts. Even so, I have heard people who attended daily Mass tell me that they didn't like it simply because there was no singing involved. In other words, they did not feel like they were able to adequately join in a period of worship without the singing.
I would imagine that the effect would be even greater in the Hours, where so much more of the essence of the texts is that of song. You open with an acclamation (which generally ought to be sung), followed by a hymn and three psalms (or two psalms and a canticle). After the reading (which need not necessarily be sung) you have a responsory (which should) and a Gospel Canticle (ditto). One can debate whether to sing the Intercessions, Lord's Prayer, and Collect. As a dialogue, the conclusion probably ought to be sung.
So essentially, at its heart, you have six or so texts which, by their nature, can be considered songs. They need not always be sung (in fact, the General Instruction seems to argue for a case by case approach to the feasibility and manner of singing each psalm). Even so, given ancient practice, one would think that the psalmody and hymn at the very least ought to be sung if possible.
I don't think there is anything wrong with a group of the faithful gathering to pray one or more the Hours using recitation rather than singing. In fact, there is a group at my parish that has started to do just that on weekdays. I find our efforts to be complementary rather than competitive. Nevertheless, just as I believe that a sung Mass will draw more people, I believe that a sung Vespers will draw more people. Further (and this is just assumption), I believe that a sung Vespers has greater ability to inspire people to recite the other hours in common than vice versa.