I transited at DXB twice over the last two months. Every time I was arriving on an Emirates flight and connecting to another carrier's flight (or opposite). The two biggest problems I experienced were a lack of a quick commuting transit system (like the mono rail at HK airport) which allowed me to cross different terminals quickly. Most of the transit desks were not operating and I needed to walk through all to see which one was available. On one occasion I arrived 1.5 hr before my connecting flight was scheduled to depart but the bus journey from parking bay to terminal took me 20min then I had to clear security and walk from T3 to T1 for transit which took me another 20 min. When I arrived at the transit desk at T1 check-in was close and I had to wait for the next flight (another 5 hr wait). This was not a pleasant experience.