I've been looking thru as much info on other S&L's as possible. Seems, all have debt of some sort. Either they owe it to their depositers and pay them interest. Or they have other sources of funds such as FHLB advances, borrowing via bonds, etc. In any case they pay interest and play the spread between the cost of money and what they can make by lending it. In WFSL's case and the case of most S&L's, their business is primarily making mortgage loans.
I guess the best we can do is attempt to find company's whose management has a good record of using good lending practices to make money on the spread.
WFSL looks to be one of those successful companies. Good location. Historically good financials. I'm sticking with it. Good luck in whatever you do.