Yes. It's an interesting question. What do we know about a person's Aikido just by knowing their style?
Not much. Their affiliation. Their loyalties (if you like). What their teachers emphasised when instructing them (maybe) and the methods by which they learned their Aikido (possibly).
I have heard people disrespect other styles of Aikido before saying "It's a nice looking style but it simply doesn't work" or words to that effect, but this opinion is always based on limited experience and I always try to keep an open mind, not judging a student by what style they profess but prefering instead to experience their Aikido in training. For all the reasons stated in the first post the ability of the student probably has nothing to do with their particular style.
In our dojo we have a wide range of ability regardless of grade, but we all learn the same techniques, hear the same philosophy from the same teachers etc but because we are all individuals our Aikido ends up different to each others. This leads me to believe that a persons Aikido ability has a lot less to do with the style they are learning than some might think!