I have had problems with Redline in the past (not on the e90). so, based on past experience, I'd take their 'compatibility' claims with a grain of skepticism.
I have nothing to say about the other options listed (although I have the same feeling for Redline and Royal Purple since the companies operate on a similar market segment). I went with Lifequard 6 direct from ZF, that way I got it for only twice as expensive as normal oil, instead of 10x for the
precious fluid.
One thing that decided me to pay the extra price is that it is impossible to completely empty the trans and torque converter. Even if the new oil is perfectly appropriate, you end-up running a mix of two oils, and that could cause some unwanted interactions.