dvanden, to expound a little on what John and Ray have said here are some of differences between the Rieco and Levelup. Some of this might also apply to the Big Foot but I am not very familiar with that system. Only you can decide if any of these points are positves or negatives.
1) Ground Control (GC) is electric with 4 indiviual motors. LevelUp (LU) uses a hydraulic pump-the same one used for your slides.
2) GC is a very simple and easy to self-install. I never installed a LU but my understanding is you have to have a Lippert or Trail Air center install the system. Still, there really does not seem to be too much to the system if you understand hydraulics.
3) As of right now, the GC is still just a manual system. You have control of all the jacks. There is no one touch button operation for automatic leveling but my understanding is that they have put the first one on Sonny's trailer in the last month. With LU, push one button and it levels the trailer by itself.
However, with that said in #3, there is no software to fail with the GC, I have read of a few failures on the LU software on this forum but it appears they were either operator error or minor reprogramming.
4) If a motor fails with GC, the motors can be switched from one jack to another very easily. Not sure what the back up on the LU is. Some one who has it could help here.
5) As stated, LU uses hydraulics so if you blow a packing or burst a line there is no safety check valve built into the system and the trailer will come down. If you blow a line on the LU, not sure if you can isolate the LU from the hydraulic system so you have slide operation. The GC is electric and CAN NOT come down due to a motor failure. However if you do not take care in running the wires for the system, I imagine you can have a wire chafe and cause a short-disabling the system.
6)GC comes with two remotes in case you loose one or the battery fails in the primary unit. You do not need a remote with the LU-(I think), just push the button on the control panel.
7)GC has 4 jacks and you can still use the rear stabilizers independently of the GC. LU, from the factory has 4 jacks, if it is a retro it has 6 jacks. The rear stabilizers are tied into one of these systems but not sure which one. It does seem strange that the retro would have 6 jacks and I do know of at least one trailer that had 6 put on from the factory but my understanding it had or has something to do with a patent owned by DRV and Carriage. The LU was either developed for DRV or by DRV and they use the 6 jack system.
8)LU is much faster getting the jack feet to the ground than the GC is. Never timed the LU but it takes about 12-15 seconds for my front legs to reach the ground.
9) No need for snap pins or extending the legs on the LU. The front legs on the GC still have snap pins and I have found I need to always extend the front legs so I have 3 holes showing below the outer jack frame. The trailer seems to be more stable that way. I think the front legs on the LU have a longer travel than the GC.
I am sure there are more differences but this is what stood out in my mind when I had to choose between the two.