Never been to DLR but Sept is one of the slowest least crowded months at WDW all year. The other 'slow' months have a few periods of busier times but Sept is pretty consistent all month. Last year it picked up a wee bit near the end but that was b/c 40th anniversary and F&W races this year that factor won't be there. The low crowds are the reason we visit in Sept every year and we have tried almost every other month (missing Jan and March) and havn't found low crowds even close to what we see in Sept.
Many rides will be walk on or have less than a 10 min wait. The headliners (except Soarin and TSM) will have 20-30 min waits mid day and can be walk on early/late. You would need to get a spot for most parades and night time shows 20-30 min beforehand but decent spots can be got as little as 10 minutes before. If you plan on dining much at TS locations made ADR's now Sept is free dinining in WDW and many resterauants book up fast.
