Logging GPS Receivers used for PC Navigation?

As I continue on my quest for the 'right' GPS solution for my needs, my son turned me onto a whole new area of GPS usage referred to as data logging. As the name implies, this category of receivers records progress for later download and analysis. Fitness training and geo 'tagging' for position linking of digital photos are two uses. (This would definitely attract my wife into the GPS world and would make a purchase more acceptable in our household...). I have seen references to a couple of these units on the forum. Units by Qstarz and Columbus are very popular according to some of the GPS hardware suppliers.

I'd like to consider one of these Bluetooth units as my single GPS receiver for nav purposes too. What are the issues to consider when choosing a logging receiver for double duty with PC navigation? Do you have any experiences with receivers that worked well (or poorly)?

Thanking you in advance,
Sailorskip