Define "better", especially when working with C-41 film in this process. The only real better I'd say for that is reducing the orange mask (which appears to be impossible without removing the emulsion), increasing exposure latitude, or figuring out what it is about Portra 400 that results in uneven looking processing. Of course for E-6 slides, it'd be nice to have a bit less contrast and to eliminate the color cast that typically occurs. From some testing, it looks like the agitation and exact temperature of the first developer matters more than the color developer for reducing color cast, though aged color developer will never result in cast-less film. It also seems like fresh color developer is more important than unused/light used color developer for avoiding casts.
For my latest testing, I mixed 5L of Fuji X-Press C-41 chemicals. I really love the separate bleach and fixer, this process is especially bad at exhausting blix, making time extensions necessary after even 1 or 2 batches. However, the developer seems to work worse for this process when compared to the cheap powder kits. When it was super fresh it resulted in minimal color casts, but an uncomfortable increase in contrast and gawdy looking saturation on Velvia (Provia had increased contrast, but no other effect). Unfortunately there was an error in my storage method of the developer after decanting, and so the developer has been aging pretty rapidly since it was exposed to some air over a week. It's no longer really suitable for E-6 processing if I want perfection, but with C-41 film it seems to work well enough (both positive and negative process).