You know, this is actually a very interesting thread. We really should have a sticky about all the different data storage systems using lasers, maybe even a chart or something. :-/
And the 1 truck @ 400km/hr vs the 4 trucks @ 100km/hr doesn't really equal because it would have to make twice the trips to go back and reload and deliver again... ;D ok, I'll shut up. ;D
Back to the diodes, should we...
Like Muridai said, comparing CDR vs DVR vs blu-ray is going to be very confusing for a noob (no offence) It's like comparing a truk, vs train, vs plane.... they are all types of transportation but completely different types of technology. SO, it is very possible to do this comparison, but it is quite advanced, it would be better to learn the basis of each one individually first.
But, in simple terms, the ir CDR burner no matter what the speed, pretty much sucks for our hobby. You should get a Stonetek 200mW ir LD for ~$10 if an invisible laser is what you're seeking, although they are very dangerous *Please research why ir is dangerous over other visible wavelengths*.
And I speak for myself but I know most of us LPF members here feel the same, but I appreciate all laser technology for what it is, so I really don't have a preference over
405nm Blu-ray or
650nm DVD burners or
532nm systems, for me they all have great attributes. It would be like comparing a few super hot ladies, blond, brunette, or black, I guess it's all a matter of mood for me. But comparing lasers and chicks never does good with me. ;D
Well I have a 6x that is totally freaken awesome, and a few reds that fill my need for red lasers ;D and a few greens that fill my need for green lasers!
btw, check out attached screen shot on how to quote