I've had one of the Grizzly 6" jointers for about 10 years, and it's
served me well. I don't remember having any significant problems with
it. With a little care in setup it cuts straight. I've reground the
knives and rechecked the setup a few times over the years. I don't use
it a lot (maybe a few times a week), but it's handy for putting a quick
straight edge on a 2-4 ft long board. The only modification I made was
a better switch mounted on a raised post behind the bed. I don't like
having to bend way down to shut a machine off!
The 6" jointer doesn't have a whole lot of horsepower, so you have to
be reasonable about the depth of cut. I regularly use mine on 8/4 hard
maple, set to take off 1/32" per pass. If you expect to be jointing
stacks of long, heavy boards, then the 8" jointer would be more
suitable because of the extra power and rigidity.
I have 6 or 7 Grizzly machines in my shop, and overall I'm satisfied
with them. They're not perfect out of the box, but with a little
tweaking and a few modifications, they've been workhorses.
Johnson's Extremely Strange Musical Instrument Co.