The Trimbles are definitely a handful and we found Terrasync easier and more straight forward than ArcPad for student use. But, it is really handy to have some Garmins (we have eTrex HCs) around for casual users or quick learning exercises.
Diana – another option to consider these days are iPads or Android devices. The expense is higher for sure, but the added utility and future expansion may be worth the investment. iPad 2’s are going cheap(er) these days and there are now add-on dongles to increase GPS signal gain and accuracy. Since many colleges and universities are buying fleets of iPads it might make sense to invest in the GPS dongles (e.g. Bad Elf) and borrow the fleet as needed. Bad Elf (who comes up with these names?) also has some bluetooth options/products.
Someday, students will arrive with GPS chips as part of their standard implant sensor system ;-).