[fcatalan]

There's a bit of "accentism" in Spain. Speaking with a southern accent will (wrongly) mark you as "lazy", "uncultured" or "unsophisticated" to some people.

I was born in Castile, so I usually speak "accentless" standard Spanish, but my mother comes from Extremadura, just a couple hours drive to the south, and when I speak to her I involuntarily switch to the extremaduran accent. I don't notice it but other people hearing me for the first time are shocked by the sudden switch.

Extremaduran accent has the same aspirated x and s mentioned in the article, so for "This is Extremadura" I'll tend to say "Ehto é Ehtremaura" to my mother and "Esto es Extremadura" to other people. Another curiosity is that many of the original "conquistadores" (Cortés, Pizarro) hailed from Extremadura.

[ttfkam]

I have never heard of Castilian Spanish referred to as "accentless" before.

The lisp always sounds odd to me. That and vosotros. The vast majority of Spanish speakers worldwide use neither.

[fcatalan]

Of course it's just another variety, but it's the one equivalent to the Received Pronunciation or "BBC English". People also tend to consider it the "original" one because, well... the language started in Castile. Up until a couple decades ago, if you wanted to have a career on national TV, radio or as an actor, toning down any other accent and switching to Castilian was a requirement, or at least would help a lot. Nowadays not so much, but still happens enough that in Spain a Castilian accent is perceived as "not having one".

[salomon812]

Northern New Mexico uses "vosotros." No one told us not to. (Or so I'm told, see my main comment.)

[prpl]

I actually learned both in high school (Las Cruces) but moved to Utah and dropped vos/vosotros. (grew up in Farmington before that)

[anthk]

Not a lisp but proper differentiation. It really helps to avoid mistakes:

za, ce, ci, zo, zu -> tha, the, thi, tho, thu. As in 'think'. That's it.

[mejutoco]

Spanish/español is also called castellano. That gives a clue as to what the standard is (not that it is better or worse than any other dialect)

[rocketbop]

Slightly off topic but your reference to being accentless reminds me of a time as a 14 year old visiting my American cousins for Ireland.

My slightly younger cousin’s friend found the way I pronounced things as well as some of my vocabulary to be very funny. When I pointed out that he also had an accent he almost almost wet himself with laughter, so absurd was the idea to him that both of us had accents rather than the one of us who didn’t sound American.

[ChainOfFools]

I've noticed strong shades of this in various dialects of Caribbean Spanish too; I didn't know there was a name for it much less a possibly correlated colonial origin.