That Sallie Mae card looks like it could be a good complement to the PENFED card, although after the 5% rewards up to a max of $250 for gas and $250 for groceries it's only 1%; but at least you get a true 1% rewards.
However, a better complement to PENFED might be the Quicksilver Cash Rewards Credit Card which offers a flat 1.5% on all purchases, which is better than PENFED's diluted 1%.
Looks like we will have to use multiple cards to maximize rewards overall. For example, we use PENFED for gas and groceries, and then Quicksilver for all other purchases, as we put everything we can on a CC to include cable, electric, insurance, etc., just to get the points which can really add up.