What recourse, if any, do I have if my employer sometimes does not pay wages on time, but does ultimately pay?

File a complaint with the State Deparment of Labor.

Unfortunately, I can't find the thread right now, but there was a long thread a few weeks ago regarding the MD DOL "running out of money" and no longer taking claims. They recommend a civil case.

How many days is/was the paycheck late?

Here is the link to the page on what remedies are available to you www.dllr.state.md.us/labor/wagepay/wpremedies.htm

Unfortunately, in MD, even before Ehrlich squelched the DLLR, they didn't get real excited about pursuing late payments. Your best bet is to find an employer who will pay you on time. If you aren't getting paid at all, or you are getting paid so extremely late it appears you aren't being paid (like if it has been 2 months and you still haven't been paid), you can file with the federal DOL.