That's the "real" Brent Spiner. The voice, the mannerisms, everything. Data is an amazing character, and Brent is brilliant as Data, but yeah, other than Data, Brent is very limited as an actor. Soong might be an exception. That one episode with Soong, Data, and Lore all in it was pretty cool because Brent was believeable as all three, and they each had distinctive personalities.
But I've seen him in a few other movies, and guest starring in things on TV, and he's always exactly the same.