I was told by a person from a rental place that rents the DVXa
and they said that the camera is awkward having just a fixed lens, that's part of the sacrifice. What do they mean by this?

What are they comparing the camera too? Only thing I can think of is that they are comparing it to an XL1s being that it has interchangeable lenses.

Perhaps someone else on here will know more about what they are talking about.

Matt,
That's really a question you should ask "them". Beyond Dustin's remarks any other speculation would be a waste of time.