Original Pranksta
I just recorded the stream of the Pat Benetar song mentioned in the article, and used Melodyne Essentials and SONAR Platinum's Region FX tempo mapping to take a quick look:
 

 
I don't think Melodyne does an adequate job of accurately mapping tempos, and the results should not be taken at face value.

 
You can see in the article what my results were:
 

 
Remember that it's essential you use the correct algorithm in Melodyne when doing tempo extraction. I forget whether I used Percussion, Melodic, or Universal...also my screen shots were generated using Melodyne 4. That might make a difference.
 
Tempo extraction isn't perfect, but in my experience it's 98% of the way there. It's easy to confirm whether the tempo extraction was successful and accurate - sync a drum machine to tempo, and see if it follows the track or not. In all the examples shown in the article, the drum machine lined up with the song.

Original Pranksta
I used Universal in my example.

Try the percussion algorithm and see what happens...
 
As to more painless tempo map editing, once a program can shift time without artifacts, we'll be good to go. We're not quite there yet.

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mettelus
These discussions make me wonder sometimes if music hasn't taken a step backwards due to computers. We went from focus on musical content to focus on visual analysis in only a couple of decades (among other issues). It is amazing that music has been made for centuries without computers, yet we seem dependent on them in today's world.

The same can be said of smartphones.
 
I started writing songs in 1977 with an acoustic guitar and a cassette recorder.  I had the musical ability in me to compose a song but I didn't have access to a beat, a bass part keyboards and various embellishments.  In 1984 I bought my first little 4 tracker and a drum machine and a keyboard.  Most of you know where this is going as you've probably gone down similar paths, but what I'm saying is that as technology grows it eventually effects everyone to the point where it makes life easier and better for all of us in probably every way possible.  Had Beethoven had access to a computer, he probably would've used one.  Hans Zimmer has been composing music scores for decades, but he still uses computers now because it makes what he does easier, as does probably every music score composer.  Zimmer eventually scores out to and uses a real orchestra, but in the process of creation he can hear exactly what the finished product will sound like in advance and make corrections or additions if necessary before he gets to the orchestra for the final product.  I don't have access to most of the instruments I use in my music nowadays and couldn't fit something like a drum kit in my little 5'x12' room, but thanks to that technology, I can make it sound like I do, at least to a small degree.
JB

Moxica
When all instruments are played by one person, I find in my projects at least, they get "inbred" as all my tiny timing errors/habits is being placed on all tracks. 
Once I had a friend replace the bassline. Same line, different person. It gave a totally new feel. No more sag.

Haha - me too!
 
In the past I've always turned my nose up at sample loops / midi loops etc, but actually I'm finding them to be inspirational nowadays.
 
Just replacing your parts with a random bass or drum loop can totally change the feel of a project, and lead things in a totally new direction.
 
I find MIDI loops especially are useful because they're so easy to transpose without loss of quality.