Don't mind Lesnar competing at the Rumble, don't mind Big Show when he's portrayed as a serious giant, don't mind Lesnar looking strong in the end by destroying (and probably breaking the arm of) the Big Show. And while they've only shared two segments with one another, I've enjoyed both.
That said, I wouldn't have minded if they had used someone like Big E Langston in the role instead. I know he's IC Champion and the title wouldn't be on the line, but it wouldn't matter. It would have made sense considering A.) Langston is friends with Mark Henry, B.) Langston is a big guy with credibility due to his size and that's obviously something they want as a part of this feud, and C.) Langston could have benefited from the rub of nearly bringing Lesnar down (even though he still would have lost the match.) Would have been interesting to see Langston come out to confront Lesnar and Heyman and they sort of just look at him as a "rookie" who Brock will easily tear through and they end up quite surprised when Big E sort of manhandles Lesnar himself.
But I dunno, I'm fine with the Big Show.