OK... thought about it a little bit more. McBackup is only here for 1 more year, so Sparks is obviously better to keep long term.
This year, we would be better off with McBackup.
However, ideally, we have our backup play 25 - 30 games in the regular season and zero playoff games.
If McBackup wins us an extra few games over Sparks during the regular season... what difference does that really make? It could be the difference between finishing ahead of or behind Tampa. But we're making the playoffs easily either way.
If Andersen gets injured and has to miss some playoff games... then this is a bad move. Does it matter if we face the 3rd place division team (probably Boston) or a wildcard team? Meh... could even be the case where the 3rd place team in our division is worse than both wildcard teams.
So the only real scenario where this hurts us is if Andersen gets injured during the playoffs. Whether we win or lose an extra few regular season games doesn't really matter much. But I think we have a good chance at the cup this year... so keeping the stronger backup for a cup run might have been worth sacrificing whatever potential Sparks has (which I don't think is much).
Anyways, probably shouldn't get bent out of shape about this... and he might get through waivers anyways in which case this isn't even an issue.