My wife and I flew into Doha after 20+ hours of flights and airports on our way from Canada. Our luggage was missing. The Doha airport was a zoo. The Al Maha people plucked us from the customs line that went nearly out the terminal, sat us down in the lounge and sorted everything for for us while we passed out from exhaustion. What a relief. They were a godsend. We got out of the airport much faster than the countless poor souls stuck in line.

On the other hand, we flew back to Doha from a holiday in Sri Lanka fearing another airport horror show, but there was no line at customs, and everything was a breeze. We didn't need Al Maha at all.

So I'd say Al Maha is an amazing service if the conditions warrant, but not necessary if you're lucky enough to arrive when the airport is quiet. If you want to play it safe and ensure a good reception, Al Maha is well worth the cost.