With the longest running Cap site (ongoing since 1993) on the web, you could say I'm a big CA fan... :D
Some have questioned the Captain America screentime and 'kick-assed-ness' -- for lack of a better word -- in his portrayal in the Avengers: Earth's Mightiest Heroes show. I hate to disappoint those who are expecting me to buy in and join their rant, but to be honest those issues aren't very important to me. What is important, IMO, is how he's portrayed in the time he is portrayed. Obviously, I can't comment on what I haven't seen yet -- still holding the line and waiting for the USA broadcasts, not covering the episodes with the Youtube uploads from Australia --, but thus far the writers have positioned him (a) as the fighting spirit of the team, (b) the go-to guy on combat tactics, and (c) the guy who is always working to make the team stronger.
Would I like more screen time, more 'kick-assed-ness'? Of course I would. But just as I find Iron Man fans kvetching over how Iron Man is treated badly, and Thor fans kvetching how Thor is treated badly, and Hulk fans... -you get the idea - a tad ....partisan, I'm not really about to work up a lather about how they're not making the show "Captain America and the Avengers".
Its an ensemble show with a large cast, guest stars, and the villain du jour; I think they've done a pretty good job thus far in highlighting everyone with good character moments and the like, building team dynamics without necessarily hitting us over the head with it.
How Captain America is portrayed is much more important to me than how often he's the focus of the show, and so far the creative team has done one kick-ass job of portraying Steve Rogers as he should be. I have no complaints.