I stayed at Disney AKL Concierge/Club last May and just got back from RPR Club a week ago. After experiencing both, my answer to your comparison question about Universal vs Disney Concierge is this:
For dealing with mix ups or issues regarding your room, package etc., it matters how and who you book your trip through. Using disney travel, the disney concierge can practically handle any request or mix up. At RPR, that is not the case. Our package was booked through Universal vacations and there was nothing the RPR concierge could do because they/Loews did not book it. I spent 2 hours on the phone trying to get it all fixed, but that is for another thread.

The RPR concierge is able to secure tickets to all parks and events or meals UNLESS you have included them in your package. Then you must provide them with a printed confirmation of your reservation. When I say a printed confirmation, there is a specific one, and if you did not bring it, then tough, your out of luck and the Concierge is no help. You must go to the quest services at the park entrance. I did have a printed confirmation from Universal Vacations, the ONLY one I ever received, but was told by the Concierge at RPR that is was not the right one....How am I supposed to know this?

They were nice, but no help what so ever, again fodder for another thread.
As for the amenities of the Club Lounges, AKL location was the bomb. The staff awesome, the food and time offerings was stellar. Some food items may not appeal to younger crowd who have not had a chance to develope their palates, but for a grown up, it was great. The Club Level at RPR is staffed with friendly people. They are very helpful and chatty. One nice touch was to offer a free cd of the music that is playing in the check in area when you arrive. The room is large and has ample tables or seat groupings around televisions on opposite ends. One side usually had local programing, the other side universals movies! You can pick from a vast assortment and they even give you control of the remote! It was not a crowded time, so that might not be the case when it is busier. My DH was able to check emails while I sat with a cocktail, ate yummy snacks and watched the Fantastic 4...They even waited on us, wanted to know about us, and were really good with remembering what we liked. For ambience AKL wins hands down, for food offerings, and people, I'd say it's pretty close except for the actual concierge services.