I'm running Redline MT90 and haven't had a problem at all. My W58 does shift smoother now, but that was about all I noticed. It's supposed to stick to the gearing and bearings really well, from what I've read
MT-90's a pretty popular choice. The only way you can really go wrong is using too heavy of a weight (been there, it sucked) or using too much (been there too, the W58 uses less than the R154 so make wure you're filling per the W58's specs).