I'm trying to figure out how a laser can work "harder". I admit fully to not knowing very much about this stuff, but as I see it, if the laser is tracking, its tracking. If it mis -tracked and had to refocus/recover over and over again, I could see that being a problem, but if your redbook audio isn't skipping then obviously that isn't happening. Its not like the laser has the ability to triple its wattage and melt itself or anything.
Again, I'm not denying that its a possibility, its just that I like to see proof of things, or at least a qualified expert opinion (ie: an optical engineer, or someone like that) before I buy into them. With hardware this old (ie: the oldest consumer CDROM drives in existence) they are going to be failing eventually. It would be a shame to blame CD-Rs when they aren't the problem.