I was always able to acheive good results with my home built oven. My blades hardened as expected (RC and file testing), and the finished blades held up well. A couple of factors steered me to buy an Evenheat. First, the Evenheat is a professionally built oven. Being professionally built, they are built to exacting standards and specs, and I can have good confidence that all is as it seems regarding temperatures (verified by the same testing of course). I don't have any reason to suspect that my home built oven wasn't operating correctly, but I didn't have as much reason to fully trust it either (aside from my testing). That being said, I do know of situations where a commercial heat treating oven was off as well, so this argument is kind of a wash. It is, however, going to likely be more reliable over the long run (I had the coil burn out several times in my home built from my own mistakes and I also had to replace the coil because of it jumping the grooves). I want to be able to heat treat a rush order without the worry that something may go wrong with my home built oven and delay me.
Another factor that steered me to the Evenheat was its controller. I opted for the Rampmaster controller. This feature gives you 12 storable programs with up to 32 segments in each. You can control temperature, soak time, and rate of temperature change (F/hr). All of that, and it's very easy to program just punching in the numbers on the keypad. I know that's a silly reason to get an oven, but this way I can program in the HT specifics for the steels I use and just select the program and hit run.
A further reason is oven interior space. My oven was about 13" deep. It was also not very tall. This made for fast oven response, but it put the blades closer to the coils, and it also limited my size of knife.
And the final reason I bought the oven is that, I love new toys.
I seriously collect tools, and this one is a great one to have and also extremely important in creating a quality knife.
--nathan
