Windsor Locks (BDL) has two different GPS RWY 6 approachs, Y and Z:

http://www.airnav.com/depart?http://...6/00460RY6.PDF
http://www.airnav.com/depart?http://...6/00460RZ6.PDF

The procedures are almost identical, and I'm scratching my head trying
to figure out the differences.

The first difference is that Z has LNAV/VNAV minima published, instead
of Y's step-down fix. Oddly enough, the step-down version gives you
lower minima. Why?

The missed procedures are equally perplexing. Y is a straight-forward
"climb to 3000 direct ERICS". Z has the more complicated "Climb to 3000
via 058 course to FARIL WP then via 060 track to ERICS". This brings up
two questions.

First, what's the difference between flying a course and flying a track?
I've always considered the two words to be synonyms. The fact that they
use two different words makes me think there's some subtle difference I
should be aware of.

Second, why complicate things with FARIL at all? The two procedures
have you flying almost exactly the same ground tracks as each other (if
my math is right, the Z version moves you about 600 feet to the left).
The only nearby obstacle is the 314 tower east of the airport, but
you're already 300 feet above that before you even begin the missed.
What's the deal here? What bit of TERPS trivia does FARIL satisfy?