Hi Leah,
When I purchased my harp, I too was considering the Christina therapy harp. In the end, I ended up deciding on the Lewis Creek Nightingale, primarily due to the fact that it has more strings (27 instead of 25).
My harp teacher has a Christina and we compared harps a few times during our lessons. Both of us agreed that the Nightingale has a warmer and richer tone. I would highly recommend to also consider the Lewis Creek therapy harps. I believe the price is pretty comparable. The Nightingale is a beautiful little harp, very light weight and ideal for therapy work. Also, I would strongly recommend going with the Truitt levers, which won’t alter the tone, are light weight and look like jewelry on your harp.
Good luck!
Michaela