I was astounded to read negative reviews about Carson Dunlop. I have been a Real Estate Broker for almost 30 years and have attended 100's of Home Inspections performed by dozens of different inspectors and Carson Dunlop and a (very) few others are at the top of my preferred list.
They are thorough, show up on time always, explain things well and urge clients (and agents) to call if they run into a problem after closing.
The types of things that are difficult to inspect are snow covered roofs and finished basements that have mould behind the drywall. They can't tear things apart and they don't have x-ray vision. But if you discover a problem later (even years) call them and they will come and have a look and help put it right. This is why so many people go back to them again and again!
When I get an inspection for myself I use Carson Dunlop if they are available and if not there are 2 other guys I like who coincidentally were trained by them.
The bottom line is that they are very good and their after sales service is second to none!