I use the ML500 for business presentations and must say that it is very bright, light, portable, relatively quiet and cool as compared to a traditional lamp projector I used to haul with me on trips. Plus this projector is way more sturdy and the lamp is very reliable (instant on, 20,000 hrs lamp life). Optoma makes a solid product. I may opt for the PK301 or PKA31 as it is battery operated.