Homeplug AV2 with MIMO: marketing, hope, reality

In a couple of months I will move into a new apartment and with this comes a new underground room and a new garage that I want to connect to the apartment.
Wifi is not really an option in this environment due to the relative positioning of the spaces and I decided to give another try at homeplug.

In the past I had a base HomeplugAV and the performance was a disappointment.
Better than wi-fi in the specific location that I needed to reach (where wifi signal was nonexistent) and useable for light internet navigation, but not an acceptable transmission layer to do a backup.

This time I went for the latest and greatest incarnation of the standard to get another disappointment.
Marketing: 1200Mbit/s
Hope: 350Mbit/s reported by the monitoring tool in the garage and 186MBit/s in the underground room.
Reality: 60-70Mbit/s in samba file transfer
It is much faster than the earlier HomeplugAV, but the marketing-reality gap is still embarrassing.

The product is clearly geared toward IT-illiterates: the monitoring tool is extremely limited.
Sometime the tool goes nuts completely: it claimed that the local adapter was not connected while at the same time a file transfer was happily ongoing.

The price for the TP Link PA8030P kit is not popular at the moment, but you get 3 gigabit ethernet ports that in many cases removes the need for an additional switch and a leading edge technology.
Should I find a way to bring an ethernet cable from the apartment I’ll quickly dump (again) homeplug, but until then it is better than nothing, better than wi-fi in the specific location and better than the older versions of the standard.
Should you have to use your electrical wiring for data then go for AV2 with MIMO: the saving obtained by using the older versions quickly vanishes once you start experiencing the even lower performance associated with the earlier version.