i had a set of minoura magrollers, exactly as pictured in kaiju-velos photo. they were fine...plenty smooth, fairly quiet. i rode 'em for hundreds of hours over ~15 years! replaced belts a couple times, bearings once. frame was a bit rusty at the end, functionally still perfect. near the very end, the plastic pulley on the mag unit drive shaft cracked. i contacted minoura directly and they sent me a whole new mag unit 'under warranty' (ie: free). that's standing behind your product!

but maybe i'm just a stupid consumer, because despite all that i believed the kreitler hype, and when a set of dyno-lytes came up on the local CL for $150, i went for it (got $100 for my well-used minouras).

the difference? virtually none. the kreitlers are a bit quieter, but lack the adjustability of the minouras. they do seem to be a bit higher quality (alloy endcaps, better welds on the frame). equally 'smooth'.

just another data point...