Just went and ordered a one litre kit so I have one in hand for later in the year when I shoot some colour negs.
I did try one of the 'Rollei C41 Colorchem' kits once, but had poor results, the negs way too dense like the bleach/fix hadn't cleared them properly, even after twice as long.
Have always had decent results from Tetenal though. It's a shame.