I prefer the ScoreCenter app over Nokia's ESPN app, mainly because the Nokia app opens the web browser for a lot of stories, box scores, etc. In addition, ScoreCenter links with my ESPN account, so when I log in my favorite teams are already selected.
The ScoreCenter app's live tile does work, it's just pretty slow. Last night it started showing the Thunder game at 0-0 around the time the game started, but it didn't update the score until almost halftime. In either app, when I get a toast of a game or news alert and click it, the app opens up at the main screen, not the game or news alert, which is bad. Also, there is never any record on the tile of an alert, so if you miss it it's gone forever, live tile or no.
I use the ScoreCenter app for news and such, and then have the SportsScores app pinned to show my favorite teams' upcoming games and scores on a live tile. It works fantastic. You can set the update interval to as quick as every 5 minutes. With wp7 it had a flipping tile with up to 4 teams, but for some reason in wp8 it only allows 2. I'm sure the dev will update it soon.