I've been using DMM airport since it was old for international as well as domestic segments. The new DMM has improved but not comfortable as Riyad but better than Jeddah. In all over Saudi Arabia non-Arabic have problems but interestingly Saudis speak English a bit better than Russian or Latin American but they insist on speaking Arabic. Domestic terminal used by 90% local Saudis so airport staff rarely speak English and if you understand Arabic and speak a bit then you will be very comfortable in any airport or any offices in Saudi Arabia. It's true that passengers assistance is poor but all international airlines check-in counters you can find expat (English speaking) with local staff.

I can't speak for Mr. Lord S. S., but my arrival went very smoothly, I really had no major problems. As for Mr. Omar Qazi, I guess either I was there on a good day, or he was there on a bad day. True, not everyone speaks English, but there are those who do, it's not that bad. As for the airport itself, it's rather mixed. The check-in area looks rather lovely, but the terminals themselves are not so spectacular, and different areas look better than others. The international lounge is much nicer than the domestic one, the dining and duty free are much better in the international lounge. The layout and interior design are also mixed; it's not a comfortable airport, that's for sure. Much better than the airport in Jeddah, but not as good as the one in Riyadh.

DMM is horrible. I flew in and spent an hour and a half being moved from one desk to another wanting this bit of paper and that, finally assembling what was needed to get through immigration. I think they are too fond of Terry Gilliam's 'Brazil' there.

The border guard who let me in kept asking questions I didn't understand. It sounded like he was asking me if I am an Argentine. Finally he let me through.

Flying out, it seemed they had never seen an airline ticket before. A small army of people huddled over my paper ticket and made three phone calls before finally letting me through.

My visa was single entry, which seems to be a meeting of the minds.

As a commuting student, I have gone through the DMM airport quite a number of times. I have also been to almost every other airport in the Gulf as well as a few others.
What can I say about an airport where no employee can speak English! This is an international airport for crying out loud. The least they can do is teach every employee some other language other than their own so they can at least COMMUNICATE to the passengers. You know, that sometimes comes in handy.