Depends on what your situation is, but I have talked to a lot of them.
King Kia has moved more inventory than anybody else in MD, but they will not work with you on anything. They will contact you about new shipments, but if you aren't the first person there offering enough money they will sell to whoever shows up, not holding a car for you at all or taking any orders (even before the SX stop order)
Kia of Laurel had no idea what was going on, I would avoid them.
DARCARs Kia and Kia of Bowie I had the best luck with. Kia of Bowie was happy to help, and matched pricing, but they are a low volume dealer. DARCARs I loved the sales manager I spoke with, but the other sales guys seemed to feed some BS or just be uninformed about what was going on. The sales manager had his stuff together, and was very helpful.
If you are not opposed to traveling a little, my go to in this area would be Abeloff Kia in Stroudsburg PA. Excellent group of people, and very clear about everything. I wish they had received the car I wanted first, because I really wanted to give them my business. Martin Kia in Delaware I also had great conversations with, and seemed like a good group to deal with.
With that said I ended up buying in Riverhead, NY at Eagle Auto Kia because they received the prestige SX I wanted, and I did not care about a drive to get it. I did talk pricing with all of these dealers, so I got to see how they were going to handle things.