Microsoft launched the Surface Book and Surface Pro 4 six months ago, and in the first quarter of this year they ratcheted up to an astounding $1.1 billion in sales, according to figures released last week. That's in the first quarter alone.

Several industry observers -- present company included -- were stunned. The Surface Book and Pro 4 have a reputation among current and former owners for being temperamental, buggy, and infuriatingly unpredictable.

But there's good news. It sounds like the massive driver update on April 19 fixed most, if not all, of the problems. The level of "I'm going to return this piece of scrap" complaints has dropped to zero. The forums that usually buzz with Surface outrage have subsided. There are still complaints about the "sleep of death," but the decibel level is at its lowest of the past six months.

What happened?

It looks like Microsoft finally got its drivers to work with the Skylake processor, Nvidia video chip, and various Intel components. It took nine versions of the drivers and firmware -- Oct. 23, 2015; Nov. 2; Nov. 18; Dec. 2; Dec. 17; Jan. 27, 2016; Feb. 17; Mar. 15; and Apr. 19 -- but the April 19 versions seems to have done the trick.

Part of the solution lies in breaking out the drivers so that they install separately, the way most drivers have installed since the dawn of time. Prior to mid-March, the updates -- called "System Firmware Updates" or "System Hardware Updates" -- arrived in a single, undifferentiated blob. If the blob didn't install, Surface customers were justifiably upset when their systems were left lying in the blue screen dust.

Now the drivers and firmware updates are broken out into bite-size pieces. The April 19 patch, for example, contained two dozen separately identified patches. If one of the patches doesn't install, at least you have the other 23.

That's what happened to me with the Surface Book. I hit an error trying to install the "Intel Corporation driver update for Intel(R) Control Logic," which cascaded into errors installing other components. I finally contacted a Microsoft engineer -- using official means, not a journalist-only back channel -- and woke up one morning to discover that everything had installed correctly.

I'm now happily humming away on a Surface Book.

My experience matches what I hear in general. The Surface Book and Surface Pro 4 now have a general reputation for being solid and reliable.

It only took six months.