Do not be concerned about using the Tetenal E6 3 bath kit. I started out using the Kodak 7 bath, and still have 1 1/2 Kodak 5 Liter E6 kits left, howvere, after trying the Tetenal. I far prefere it. Results just as good, and much much simpler and more user friendly to mix up and use. Bear in mind that the Tetenal3 bath kit has been around since at least 1992, and is very high quality, German engineered (and made in Germany) chemsitry. The Tetenal 3 bath kit, and their Blix in particular is suited to home use, with the chemistry being designed to make 3 runs before being discarded, without silver retention issues. For us home users this is perfect. For large volume lab usage though, it is not (and was not designed for this). With the Tetenal Blix, you must use it within 2-4 weeks of mixing. I do all 3 runs in 1-2 weeks, as I shoot a lot of E6. The advantage of the 7 bath Kodak and Fuji kits is for lab usage, where initial chemistry is mixed up, then kept constatntly monitored and replenished, as many many films are run through. The 7 bath is stable and controllable for this type of industrial style usage. With mass film development, proportional chemistry costs are far lower than with blix based systems. The Teretenal 3 bath blix kit is not suited to such industrial scale usage, at least not at the same costs. - it must be mixed and used 3 times, then discarded.
But this is not an issue for home users. In fact, it is perfect. Far cheaper than buying 25 gallon quantities of 7 bath E6 chemicals, the same quality, and much easier and simpler mixing and processing.
I too did much research and was leery before trying the Tetenal kits. But I dont remember ever finding a single post with people who had used the Tetenal kit yeats ago and now have fading or other issues. And the results after trying spoke for themselves and ended all questions I may have had. Sparkling, beautiful chromes, with good skin tones, good dynamic range, great colors, and no issues with retained silver.
So, I highly suggest giving Tetenal a try. The 5 Liter kit works out to less than $2/roll, and you have same day results if you desire. Check out Freestyle Photo in the US. Avoid the Arista kits, they dont include the required stabilizer, and have other issues (see previous posts). Lower quality stuff, and you dnt save much either.