Based on the number of posts I have seen on various groups having issues with hydraulics we went with electric. The two models of Grand Design were looked at had one with electric and one with hydraulic. Solitude 2930 and Solitude 310GK
Advantages to Hydraulic jacks and slides:
Much faster
Hydraulic has a higher rating for weight and will lift the wheels off the ground.
Advantages with electric:
Lower weight
Less components and complexity. Less to go wrong.
Less Maintenance.
Easily serviced by myself with simple hand tools. If a motor fails I can replace it myself. If a front jack motor fails I can take one of the rear and still be able to hitch.
In the end for me I would rather it take longer for the trailer to level and have a simple system that I can fix myself. During the minute or two it takes to level I am busy anyway pulling our chairs and setting up camp.
I liked the fact that it reduced weight. As full timers we are already pushing the GVWR of the trailer. For some of the same reasons we also didn't want electronic command systems to turn on lights etc.
Give me simple and something I can repair myself out in the boondocks.