Beta Readers and Diversity: Focused or widespread?

I was reading this post: http://tranifesto.com/2012/05/03/ask-matt-writing-a-trans-character-in-fiction/

Overall, I like it and the discussion. There's a commenter who goes way over the top, IMO, criticizing the person who asked the question for even asking the question, since it supposedly objectifies trans* people and portrays us all as a monolith, which kinda bugged me. There are things that are generally good to do and generally good to avoid when writing about trans* characters even though we're all individuals. For instance, avoiding stereotypes and language that cis people don't get to use, or making sure the character's multi-dimensional and realistic, not defined by being trans.

At some other point a commenter called palacinky says:

I agree with the advice about getting feedback from several trans women (ideally people who have a vaguely similar backgrounds and identities to that of the character you’re writing). In other words, don’t ask trans men what they think about the trans woman character (and vice versa), don’t ask a gay man who does drag what they think about the character, if the character is black or latina, then ask a black trans or latina woman for their feedback. Try to not be defensive when you hear the feedback but also understand you’re writing a unique person, hopefully not a trans cardboard cutout or token. And first and formost, you’re writing a WOMAN character not “a man who wants to be a woman.”

I find this advice interesting and am not sure about it. Yes, get at least 2 trans Latinas if you're writing about trans Latinas--but I'd actually have given the advice to specifically include reviewers from other identities under the same umbrella. You don't want to accidentally write things that affirm trans women while denying the existence of trans men or nonbinaries. Similarly, even if your character's white, you probably want a beta reader of color to screen for racism. I think with the trans umbrella in particular it's really easy to fall into definitions and explanations that completely erase entire swathes of people, and while your character is going to be an individual with experience as only one specific trans person of a specific identity, you do run the risk of characters or authorial voice saying or implying something offensive to other sorts of trans people.

So, I'd say, ideally both, but specific is probably more important than broad.