The lower tension on older harps is easier on the hand because the player doesn’t need to pull as hard on the strings to get volume. These harps often have straight soundboards (as opposed to extended) but do not necessarily lack volume. Many have projection far beyond what you might expect. This also depends on the quality of the restoration. Many harpists say these instruments are very responsive and a delight to play.
The harp I am having restored is a 1920 L&H #22. (Looks just like a 23 with on less string and is slightly smaller.) I has an extended sound board. It would not have the tension of a more modern instrument. Would this limit me in the future? Would I be able to play higher tension instruments without a great deal of difficulty?