I'm with the Church of Religious Science.
In general, Unity is very legitimate, and is not a cult.
Both of the above faiths are New Thought Churches (NOT New Age, which is externally-oriented). "As you have a new thought, so shall you have a new experience." All of these churches (Divine Science, CRS, and Unity, Christian Science) evolved at about the same time. Many of their founders had studied the great philosophers and Master Teachers, everyone from Jesus to Thoreau and Emerson.
The main difference is that Unity is a Christian-oriented philosophy, whereas, in CRS, we believe that Jesus was a Master Teacher (to the max, if you will), and we study all of the Master Teachers, regarding them as equal. Basically, Unity has a more "Christian" flavor (not trying to be offensive - just clear).
Both are considered to be into "metaphysics." Don't be scared - I'm a law graduate and a retired social worker, in my 40's. I have a Master's Degree in Psychology. All this is is good cognitive-behavioral psychology, in that it encourages the parishioner to use the power of his or her mind.
Of course, I said "generally" up above, because, although I encourage DUers to attend various services at various progressive churches (and, yes, Unity is one), I prefer that each DUer take a look at the individual congregation, and make sure that everything seems "common-sensical," so-to-speak.
We follow many of the same traditions, such as celebrating the seven attributes of Spirit (God) at Christmastime.
I have been involved in CRS for over a year; no one has told this independent broad what to think, with whom to hang around, or attempted to isolate me or anything bizarre.
I have posted informational links below:
http://www.rsintl.org/http://www.unity.org/The first is for CRS, the second for Unity.
I have a very close friend who loved attending Unity (she used to be married to a Methodist minister - and she is very well-grounded, and a member of the reality-based community).
I hope this helps. Let me know if I can help in any other way.
Blessings to you!
On edit:
Sorry, you already had the Unity link. I think that Californians attend CRS because it got started out here, and it is very 'big' out here; the same for Unity - only its base lies more in the Midwest, I believe.
I'm giving you some info from my pastor (I'm taking a good historical church course).