No one has opinions about the strings i mentioned?
What's the gauge of the lo-rider nickels you're using?
I've heard that these are too harsh to fingers, though I've never had a chance to try them out.
As a nickel string lover, I've tried, among others, DR Sunbeam, Lo-Rider (nickel), Sadowsky Blue Label Nickel, La Bella nickel, and of course, MTD Nickel strings.
Since Sunbeams (round-core version of Lo-riders) sound a bit on the darker side, I guess it's not surprising that Lo-riders sound relatively dark, too. That "darkness" in tone may sometimes be related to a "muddy" feeling, but it still sits very well in mix to my ears – you're playing a MTD after all!
MTD's nickels sound as perfectly as the SS version (on an aggressive side IIRC), though it won't last very long before the brightness disappears (mine becomes dull after one week's heavy playing).
Both Blue Label and La Bella are smooth and bright. You may want to check them out and give them a try if you love the tone of Lo-riders – they tend to more mid-focused, though.
For best clarity of a low B string, try .135, and you'll be surprised. Just my 2 cents...