Can only really go on my experience with the Tsumura reduced weight bars as they are the only RW I have used. I still consider them solid bars, as opposed to laminated. Perhaps I should be calling them reduced weight solid, rather than just solid? The Tsumura RW solid ones have held up well for me. As well as the standard solid Tsumuras. Have only ever had problems with either cheap solid bars (come to think of it, was soft rails, not the bars bending or not bending back easily) or laminated bars (never lasted long enough to accurate gauge rail wear).
If it were just one laminated bar rather than quite a few (I should probably point out also none of them have been stihl laminated bars) then I might have considered not piping up. But after three, I gave up and returned to solid or RW solid. But I'm probably a fringe case and the majority may not notice any difference between their laminated and solid bars.
The main reason why i keep searching for 18-24" solid picco bars is because the laminated haven't held up for me and while I like the cannon picco bar, I still haven't put enough time on it to feel anything but uneasy about the nose. Just a gut feeling it won't hold up over time. Hope I'm wrong.