XSLT 2.0 and XPath 2.0 Programmer's Reference, 4th Edition (346 page)

is false.

But although these operators were introduced specifically to enable XQuery optimization, I think it's a good idea to get into the habit of using them for most routine comparisons. You probably won't see any very visible performance benefit for the average XSLT stylesheet, but you may find that you make fewer errors because the behavior of the operators is simpler and more predictable. As a bonus, it's easier to write
le
than
<=
.

In the XPath syntax, the two kinds of comparison operator, as well as the three operators
is
,
<<
, and
>>
, which we will meet later in this chapter (see page 594), are presented like this:

Expression	Syntax
ComparisonExpr	RangeExpr ( (ValueComp | GeneralComp |NodeComp ) RangeExpr )?
ValueComp	eq | ne | lt | le | gt | ge
GeneralComp	= | != | < | <= | > | >=