Whether single or multi-piece packs. The only advantage is the price. The units are identical. I have bought 2 duopacks. One as a router and 3 as satellites (nodes) in use. Flawless.
Under the following link you will find a comparison of all the data known to us: https://www.digitec.ch/de... . According to research, it should be possible to couple 2 units of the single device to a satellite solution.