Steve, I've got the 350 not the 300 but as far as I can see they are much the same other than for power and dimensions. I use /abuse mine and have had no problems with it. My most recent task was to deepsaw ash 185mm wide and (with a 3/4" 3 skip blade) it did it easily.
My only gripes would be the ease or otherwise of adjusting the lower guides and the flimsy wheels on the pedal wheel kit (or rather the flimsy metal bracket that holds the wheels and buckles)
Decide what you intend to use it for and make sure it can be done with the 300. if you go to the show there may be other makes to compare against.
i bought mine at a similar record show in Peterborough. I wrote a review that you should be able to search for