If you want a comfortable and reliable SUV, go with the Lexus. If you don't care about reliability as much and want a sportier driving experience, go with the Mercedes GLC. I'm not a big fan of the GLE as it is not as up-to-date as with the rest of the Mercedes lineup. The Acura RDX is also really old-feeling. The MDX will be the largest and most practical while also having decent reliability. The infotainment is from the late 2000s though. If it were my money I'd take the Lexus RX, but if you plan on a short ownership buy the GLC.
For a family, the MDX seats 7 or 6 with captains chairs and is the most pracitcal. It is pretty nimble, too, for the size with SH-AWD. The interior quality is not really on par with the rest of the segment. The RX is the second most practical for a family. If you only need 5 seats and a large cargo area, this would suit you better. The RX is the most comfortable and reliable SUV on your list.