Depends if you're talking total compensation or just straight pay.
Southwest F/As are in the middle of contract negotiations right now, so it probably wouldn't be a good time to make straight pay comparisons. Straight pay is usually lagging at the end of the contract in comparison to other airlines. I do know, however, that when I chit-chatted with one of the F/A union reps onboard one of our flights a couple of years ago (about midway through the contract), he told me the pay was comparable to the other airlines. And total compensation, he told me, put them above many of the other airlines.
You have to realize that 1) compensation includes more than straight pay. You can get a great paycheck, but if you're paying out the nose for your medical insurance, it doesn't matter. And 2) your airline is selling you some serious koolaid when they tell you that Southwest employees don't make as much as the other airlines. Check out the latest and greatest contracts with Maintenance, Ramp/Ops, and now the CSAs/Res Agents. Pilots may not be making as much straight pay, but when all these concessions are said and done, I think they'll find they're making more, and without the painful layoffs.
I think you'll find at Southwest that the pay for contract employees is competitive, and the benefits are a heckuva lot better. The real difference at Southwest, IMHO, is in the workrules.