There all the same! If it looks like the same design, then it probably is the same. Some might be a little better assembled, a little cleaner, better adjusted and QC'd, but they are all made from the same components. Ive only seen pictures of the Jet Mill, but its essentially the RF 31. They also sell the 9x20 lathe (at 1500.00). I have a wood shaper from Grizzly that they sell a version of. Jets a great company for service and warranty (2 Years), They may have an american motor in thiers, but your gonna pay for the pretty paint job! My Harbor Freight 33686 was so sloppily adjusted that it was essentially unusable the way it came shipped, but it is the cheapest of the bunch. After re adjusting all the moving parts it is as good as any of the more expensive ones. I use mine everyday and I am blown away at how fast and clean the thing cuts. Today I was cutting a sword blank out of CRS with a 3/4 end mill cutting the full blade profile and chunks of metal were flying 7-8 feet off the spindle with not even a hint of hesitation or vibration. The thing screams through metal!
Halfnutz
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)