Firstly, most prospective purchasers should also consider other similar models such as the many versions of eTrex or the GPS60, because this is rather a "specialist" device. That one of its main features is that "it floats" is a clue that it's particularly intended for boating. This also explains the retention of a RS232 "COM" serial port, compatible with the NMEA interface used by marine devices.
The original GPS72 design is at least 7 years old and the user interface has hardly changed from my first GPS purchased more than 15 years ago. However, the high sensitivity receiver and addition of a USB connector are very worthwhile improvements in this new "H" model. Other positive features are the relatively large screen and the number of front-panel buttons (well-labelled and most backlit at night) giving a generally easy user-interface. It's "transreflective" monochrome screen remains clear in the brightest sunlight, with an adjustable white backlight at night.
For data entry, with most modern Garmins (like the GPS60) you "pick" characters from a two-dimensional tabular array using the joystick/pad. However, this model employs a continuous "ring" of alphanumeric characters and symbols, which I personally prefer. It does take longer to enter characters from the latter part of the alphabet, but number-only fields actually can be quicker and it's possible to enter characters purely by "counting" button-presses without my need to put on spectacles !
On the negative side, the memory size (for recording tracks) is very small for a modern device and the "support" from Garmin currently rather limited. The CD in the box carries only user manuals, there is no software like Mapsource, as (normally) included with the GPS60. You have to go to the Garmin website to download USB drivers and find/buy some software to manage the GPS data. Some areas of the website even deny the existence of the GPS72H, but generic USB drivers are available there and work well.
A fault that I've found is that the Trip Computer Odometer under-reads on slower walks. It's possible to find the true trip distance by "saving" the track and reading its properties, but this must be done immediately after a walk because this model doesn't have as much flexibility as the GPS60 in selecting sections of track. A (rather delayed) response from Garmin Support to "Update the firmware (to 2.30) and factory reset" may have improved the accuracy, but the odometer still appears less accurate than my previous handheld GPSs.
For me, this was the best choice of GPS because of the "plus" points above and particularly because I can connect it (via the serial interface) to my Pocket PCs running Memory-Map. This gives almost all the Desktop/Laptop features of M-M in a completely portable package, e.g. on holidays. But serial ports (and even PPCs themselves) are almost obsolete now; BlueTooth might be used with a Smartphone but a BT adapter and the proprietary Garmin cable will generally cost at least £50.
In rating the GPS72H I considered withholding two stars because of the limited memory, inaccurate trip odometer and unusually poor support from Garmin, but decided to dock just one star to compensate for the (IMHO) rather harsh rating of the other current review.