We have used Universal on a number of occasions, operating in the Caribbean (Aruba, Dominican Republic). They assign a team to your flight and its a simple phone call to speak to someone that knows what your plans and situations are. They also took care of getting us a permanent CBP overflight permit so that we don't have to stop in Florida to clear customs any more. It has gotten to the point that we have somewhat of a personal relationship with the flight planners, so thats definitely a plus.
Costs seem pretty reasonable for the level of service that you are getting. If the boss is spending 50k to fly to some far away place, whats a couple thousand to have the piece of mind that your flight plan will be filed correctly and someone will be there to meet you on the other end and basically walk you right through customs. Universal handlers are guaranteed to speak English, and that can be VERY helpful in some far away lands.
Fuel can be added to the final ticket, so you don't have to worry about currency exchanges and all that good stuff.
I've used Universal before. Some things I like. The handling is excellent, but in Rio the charges were huge. I've had some trouble with them changing our route on us based on their flight planning software vs ours. You are right about customs.