You seem to have overlooked the Lowrance models - even in your basic segment. Are you not sidesteeping giving information about a useful piece of kit. In my expereince the Lowrance does as much as many other more expensive models.
Lowrance models haven't been mentioned, along with a few other manufacturers. The main reason is that we've concentrated more on the most widely available models in the UK. Lowrance is a much bigger name in the USA than the UK, where Garmin and Magellan dominate along with the emerging SatMap Active 10.
Lowrance was a big name in marine navigation, a name featured prominently on Royal Navy navigational and electronic IDFF equipment in the 60s and 70s. That should suggest a pedigree of sorts.
I appreciate what you say about concentrating on available models in the UK - I was able to source and recive a Lowrance GPS unit easily and having shared its potential with others was pleased to discover that they are now buying Lowrance. I guess I am just a Lowrance fan!!
To be fair, in an article published 'in association with Garmin' (i.e. sponsored by Garmin, I guess), would you expect to see a lot of the competition's products mentioned?
That article is clearly intended to give an introduction to the four basic types of portable navigation device:
entry level, giving just position and route
mapping models, providing mapping
advanced models, with other features
PDA-based PNDs
It does that, giving examples from Garmin's range, and some other examples.
It's clearly not intended to be an exhausitve list of all available GPS devices on the market.