I took this trip as a solo travel/volunteer trip to Ecuador. United Planet had a really great support system and was very organized throughout the application process. They were all prompt with responding and the in country staff was also prompt with travel accommodations to and from the airport..
I'm a PA, certified and all, so I was hoping for more experience and exposure to the under-served areas of Quito, where healthcare is not readily accessible and where I could be of more help. However, I was placed in a private clinic to observe, which I did appreciate observing how things are done differently vs in the US. The spanish classes were great, b/c I'm not very fluent in Spanish but with my broken/basic spanish, I was able to communicate with most ppl. Most of all, I really enjoyed having the complete independence after the first day, which meant I got to explore the city of beautiful Quito. It was so fun!
Quito is actually really safe, compared to even some cities in the US. Be smart about traveling at night. The most common crime is pocket thefts in crowded spaces like the bus/trains. I would highly recommend the trip to students, but as for professionals, I would inquire about what you'd be able to assist in b/c you might be observing more.