The whole point of paying to get an inspection is to have a qualified professional observe & document the home’s condition and defects. And it usually takes about 3 hours to complete the minimum standards of practice that most reputable inspection associations require (such as NACHI or ASHI).
If the home inspector doesn’t take his time to really observe the home’s systems, if he just “goes through the motions” in under 2 hours, if he’s rushing through your inspection to get to the next appointment, he is not taking enough time (except in very small or newer homes), and defects can be missed.
If you’re paying a professional, you should get professional results, but this is not always the case. Your family’s safety and your biggest investment deserve a thorough home inspection as explained in this What is a property inspection article.
Different inspection associations have different “Standards of Practice” and even these are minimum standards! While most inspectors are required to inspect the home’s major systems to find defects (what many agents call “the important stuff”) like major structural damage or major electrical problems, lesser (but still important) defects and concerns might be missed entirely–or worse, they might get “candy-coated” by a biased or less-than-thorough inspector.
The bottom line is that using the wrong home inspector can result in substantial, costly repairs coming out of your pocket later. Not to mention the repair costs associated with lots of minor defects (they can add up quickly).