Some Denver area Realtors I know use the same home inspector for every house they sell and many Realtors have been using the same inspector for many years. There are a lot of positives in working with someone you know you can trust and rely upon to do a good job for your home buying client. Never the less, I have a in-town Denver home buyer who is getting an inspection tomorrow on home that was built in the 1900. I would say that qualifies for an "older" home. And, the house does need some attention to deferred maintenance items. In this case we have selected an inspector that I have used occaisionally over the years especially on "old" homes. This inspector is experienced with older houses and has proven in the past to understand some of the idiosyncrasies of an older home.
On certain occaisions with unique circumstances of a house, it can be extremely helpful to hand pick the home inspector based on their area of expertise and experience. Some inspectors have an engineering degree and may be a better choice for a house with structural issues. I have another inspector who by far does a better job on taking a really close look at gas, forced air furnaces that are over fifteen years old. He will actually take the blower assembly out of the furnace in order to get a better look and test of a combustion chamber to see if there are any cracks. A simple mirror on an extension cannot see all hidden cracks that may exist in the combustion chamber or heat exchanger. And even this inspector is not hesitant to say, "In this case you should have a qualified expert do an inert gas test in order to be completely certain there are no cracks."
If someone is going to do an addition to the house they are buying, one might use a home inspector who in an earlier life was a home builder. Early in the buying process this inspector may save a lot of time for a buyer that will enable the buyer to move forward with their plans or perhaps educate the buyer to the fact that they may need to modify their home addition plans.
If you don't know the background of an inspector, get references and check what industry certifications they have. Remember, in real estate there is no dumb question!
