What do you like best?
For GIS data collection TerraSync is fairly quick and efficient. Using a taylormade 'data dictionary' improves productivity and can help minimize error when collecting desired features. Pending how these dictionaries are setup it can force required fields be meet for accuracy, minimum time a feature will be measured, all or some data descriptions that must be entered to label items & automatic data/time when items are collected. User friendly with organized drop down menus to switch between tasks easily. Best suited with some office preparation before field use. Auto-pan to location as you move around or from site to site. Able to load a variety of background data like geo referenced images, SHAPEfiles or AutoCAD DXF files. It's been fairly easy to instruct those with little or no experience in the operation of the software while still obtaining results.
What do you dislike?
The overload on systems related to datums. While it's good to have a large range to select from the system used should be more intuitive and filter out unnecessary items. For example I can select [System]US State Plane 1983 [Zone]California Zone 5 US SF and under Datum I can use NAD 1983 (Conus) CORS 96 among other NAD 83 related datums. It also list datums for places like China, Netherlands, Ethiopia etc.. It seems to me all this extra information was just thrown together and is a bit sloppy. You have to wade through all this extra stuff till you find what you want or need. Worse it could cause error for someone not familiar with GIS or GPS work flows.
Recommendations to others considering the product
Request a sales demo or presentation. It might help you understand the functionally a little bit better. It's a little high in price but has been easy to use with little to no glitches or defects. The only thing that has restricted this product is satellite reception or multi path issues to the device TerraSync is loaded onto.
What business problems are you solving with the product? What benefits have you realized?
This software was purchased specifically to update city/county GIS maps on items for man holes, catch basins, fire hydrants or other utilities. Generally for these items a survey grade measurement isn't required and would be too costly. Other uses have yet to be implemented at this time.