I can't wait to try a Quadchip - the feedback seems to be very positive!
I haven't experience any particular jamming issues and I run 2x 1928 machines. Every chipper will jam on the odd occasion - it seems very unlucky for you to witness this twice. For some reason our road tow actually seems to feed slightly better than the Safetrak, but I can't really determine why this is (the top control bar on the road tow is a lot better for avoiding unwanted branch 'trips' than the lower Safetrak version, but this doesn't have any other effect on actual chipping performance). The rotor/feed roller set up is identical on both machines, and they have both done similar amounts of work so are pretty equally worn.
I have the stress control set up more along the lines of the Timberwolf - you can re-program the Greenmech box to suit individual operator requirements and I find this works very well for me.
In reply to tommer9, I think I have mentioned quite a few reasons as to why I think so highly of Greenmech when compared to other makes. Maybe I've been lucky and only used really good ones?!
The reason for starting this thread was to thank Greenmech for their excellent support - my opinion is based on my individual experiences of dealing with them as a company. I have spoken to people in the factory who could easily have fobbed me off and pointed me in the direction of a dealer, but who take it upon themselves to offer any assistance possible over the phone. This is priceless when you need help there and then, and can save downtime along with the obvious financial implications.
It is apparent that people have mixed feelings about the brand - I'm sure that some people had negative experiences with the older/earlier models and are subsequently put off the entire range. I have used 2 different models of older Greenmechs that were absolute dogs - not a patch on the competition. However, the later machines in the range are leagues apart from the earlier stuff. Even though they use the same disk blade system it appears that there has been a massive evolution in the design of the flywheels and the way timber is presented to the blades, which in turn affects the feeding and subsequent chip ejection.
I think the company and the machines are brilliant, and I would recommend that anybody in the market for a chipper at least has a demo on one - if it turns out that a competitor's machine is better suited to your needs then at least you'll know for certain!