Both my boys went to Sunshine Preschool in Parker and I now work there as the Assistant Director. I'm a little surprised to hear some negative things (Sunshine won Parker's 'Best of the Best' preschool for 2005 and 2007!) but everyone looks for different things in a school.
To clarify however, the teachers are highly qualified. Several have bachelor's degrees in Education and all attend a minimum of 15 continuing education hours in Early Childhood Education per year. The owner and myself are both Director Qualified by the state (24 semester hours in Early Childhood Education and minimum of 2 years of work experience).
The school itself has been operating in Parker for over 10 years and has been in it's current location for 7 years. The owner of Sunshine has over 13 years experience working in preschool and she taught both my boys. My 7 year old now attends North Star Academy and has done very well, in part I'm sure because of the great preschool education he received at Sunshine.
The curriculum at Sunshine is Core Knowledge Friendly (a great plus if you are considering a charter school after preschool) and all classes teach Spanish and sign language. The children do one worksheet daily to practice their writing, this is about 10 minutes of a 2 1/2 - 5 hour day so I would hardly say the curriculum is "worksheet based" as someone stated.
The nice thing about Parker is there are many, many amazing schools to pick from. There are several excellent Christian preschools, two preschools that I know of that offer Montessori programs, and some good programs that go through Douglas County Schools. As far as I know, Sunshine is the only Core Knowledge Friendly school in Parker.
The best way to decide is to visit the schools yourself and decide which is the best fit for you and your family. All licensed schools required background checks on their employees and you can also call the Division of Childcare to make sure the school's licenses are in good standing.
After a tour and meeting with the staff, you'll get a gut feeling about which program is the best fit for your child. Best of luck in your search, I'm sure you'll find a wonderful school for your son!