My very first darkroom experience as a mere lad was processing Ektachrome-X in E4 and even doing a bit of E3 (with it's manual re-exposure to to a lightbulb step) in my Dad's home darkroom. Since then, many years of working in studios, labs and freelancing in multi-image production houses gave me the opportunity to work with, and the responsibility to maintain process control for dozens of E6 processing machines of all types and makes.
E6 was really designed to work best in a Dip and Dunk processor or a sink line with seasoned, replenished chemistry. A couple of of the steps are intended to occur without agitation, which is obviously impossible in a rotary or roller transport process. Even then it takes constant plotting of each color with a densitometer and chemical and process adjustments to keep a line in control. Keeping a commercial E6 line within Kodak's specs is two parts science, one part art and one part voodoo. I would guess that the footprint on OleTj's film is a pretty good hint that his lab isn't particularly scrupulous about fine process control.
It may seem that one-shot processing would be at the very least the most repeatable process, especially if you mix your stock solutions in quantity but I've run Colenta and Wing-Lynch rotary lines and found them infuriatingly difficult to maintain consistency on, run to run.
All that being said, I wouldn't hesitate to process E6 at home, tanks and hangers or invertable tanks is best but if you are doing rotary, follow any recommendations and adjustments that the manufacturer publishes and use your most disciplined and practiced processing techniques. It is a critical process. Also, use all safety precautions when handling the chemistry. Good ventilation, rubber gloves, I recommend a stylin' Black plastic Kodak darkroom apron and by all means protect your eyes. They eventually got rid of the formaldehyde stabilizer but there are some truly nasty acids, bases and bleach involved. I've run both 3 and 6 step E6 in my Jobo. I was pleased with the results visually but I have an uneasy feeling that if I had run a control strip and plotted it, I would have been horrified.
Bottom line, If you have specific needs, like a lack of access to a decent local lab (becoming a common problem) or strict turn-around requirements, and can justify the extra expense and effort or you just enjoy relaxing evenings in the darkroom and "doing it yourself", home E6 processing is certainly worthwhile , _But_ if you can hook up with a good lab that has a dip and dunk processor, runs scads of film every day and maintains critical process control (yeah, right), that is where you will get the ultimate in quality and consistency.