The drop shipping option just removes the DealExtreme branding from the packaging, it makes no difference to the actual shipping. If your order is $15 or more (?), they'll ship it registered mail which I find is a few days faster and has a tracking number. You can also upgrade to registered mail for $1.70 if your order is under the $15 threshold.
As for the OP, I've placed probably 100 orders with Dealextreme and they have all arrived with no major problems. Around Christmas last year, it took a MONTH (or more) before they shipped out the item, and good luck with finding any backordered item in stock ever again, but other than that if you're looking for affordable products and free shipping, DX is THE way to go.
Items that will "ship in 1 to 3 days" or "2 to 5 days" will realistically take longer than that, sometimes a few weeks before they ship. If you need something urgent, don't order it from DX - even selecting the EMS shipping won't do much as I heard around the DX forums a lot that EMS is held up in customs more often and it does nothing to improve the dreadfully slow internal processing time at DX before the item even reaches the post office.