Actually the industry hasn't learned how to use it, at least not entirely. Solder paste manufacturers are still to this day trying to come up with new formulations to reduce voids, especially in BGA's. Voiding is a big issue with modern consumer electronics which are all manufactured with lead free. In my opinion, there was no need to use lead free in the first place, and it's an inferior product at this point.
In fact, I just fixed a girls Sony laptop a few months back that wasn't even a year old because the BGA video chip needed to be reflowed to work. I took it apart and put the board on my rework machine and fluxed it and reflowed it. I'm a SMT process engineer and do this everyday, and I have seen a lot of failures contributed to pb free solder. I personally think it sucks for a number of reasons.
I also cannot think of a case where the higher melting temperature is an advantage. Every component on the board has to be subjected to considerably higher temperatures, and heat is never a good thing for electrical components. Sn63/Pb37 melts at 183c, a typical SAC 305 melts around 220c. You have to heat the board and components quite a bit more, at least 30 c more, on a pb free board vs a leaded assembly.
At the very least it has gotten a lot better then it used to.
Back in year 2002-2007 there where really serious problems with the solder, especially the Mobility Radeon sereis GPU's up to the X300/600/700/800 series.
And of cause the infamous Geforce 8000 series.
But those are pretty extreme cases, temperatures can go fro 50C to 80C in seconds, the chip may dissipate between 25w and 100w I'm pretty sure this would stress leaded solder as well.
Before the change to lead free solder, computer components didn't produce quite as much heat as modern ones.
So I don't think we can blame lead free solder exclusively, the challenge of bonding a high power chip, with very low idle power draw and hundreds of pins to a PCB is very difficult.
Also, the general quality of laptops has gone down since 2004, everything has to be thin and light.
This makes making a rigid chassis a bigger challenge, especially if you want to keep costs down.
With a flexible chassis, the motherboard in the laptop, will flex as much as the chassis, this will ruin leaded or lead free soldered mobos, it's just a matter of time.
Many people see no problem with holding their laptops by the corner, this will flex the chassis a lot, all the weight of the laptop is held by a very small area of contact and will stress even the toughest of laptops.
Also, a thinner and lighter laptop is easier to hold by the corner, making people more likely to do it, making failures more common.
