The Honda scanner can also do things like program remotes (sometimes this can also be done without one) and access advanced diagnostic data that isn't available over ODBII. Also it can pull ABS, Air Bag codes, TPMS sensor registration, etc. It can initiate various re-learn procedures as well, among other things.
There are other products such as AutoEnginuity that can do some of this (but not all of it - check their web site for details on what is supported) for less money.
Honestly, a simple ODB II scanner that supports viewing live data is sufficient for most DIY work. I don't know what the independent mechanics use... I know there is some very capable aftermarket stuff that works across brands. Dealers of course use the "official" scan tool.