A higher level of wattage only means it’s hotter, but that doesn’t guarantee a better blowdry experience. More horse power in your car doesn’t mean it’s more efficient. It doesn’t means it’s better.
Quality of construction – As with most purchases (certainly not all) you get what you pay for. Generally a Professional grade hair dryer will be built using higher quality parts and come with more of a guarantee.
Design – Aside from looking like an Italian sports car, a hair dryer’s design will have a great impact on usability and performance. A pedigree, salon tested model will have the benefit of testing in a high use environment. Hopefully the manufacturer would listen to feedback and improve their design over multiple versions. It is surprising how much difference making the power cable two feet longer could affect the ease of use.
Materials – Once again, higher grade equals better materials. If your hairdryer has low quality motor parts or the plastic casing is not greatly heat resistant the decline in performance will be reduced over time.
Power + heat = speed – In a salon environment time is money and the investment of hair dryer that reduces your blow drying time by five minutes would pay for its self in a very short time. If you want great results in a shorter time Then perhaps a Professional Hair Dryer is for you.