I have the KM14D. Its a fine little furnace, but I will probably buy another one soon. The reason why I want another is because this one is 120 volt. It takes a coon's age to get to 1950 or higher. I am convinced that it is because the 120 volt input can only yank 16 amps max out of the line, and therefore is slow to ramp - even at a max ramp speed setting. From room temperature to 1000 degrees it is very accurate and works extremely well. So I think I will get another one in 240 VOLT and relegate this one to tempering duty.
Incidentally, I bought this one direct from Paragon. They'll definitely deal over the phone. I had it within a week of the phone call - made fresh just for me. Oh and you can also ask them for any door or interior configuration you want. I have the long and narrow chamber, but a friend of mine got the side-swinging door and a wider, less-deep chamber. I like his alot, but mine will fit 16" of steel diagonally. He does nothing but folder blades, so he could care less about a long chamber.
All this said and done, I'll buy the new Paragon just because I already own one. Hopefully the paint will match! LOL!
~BUT~
...if I had to do it all over again I would get the Evenheat because I don't see much difference in quality - only price. After all, its merely a few fire bricks and some electronic guts and some sheet metal. Its not like you'll be tossing it around in the air with your friends every friday night, either. I say go for price.