Only very seldom there is actually someone at the reception. You need
this to get the (complimentary, so this is good!) wlan code tickets
(which seemed to be expired really soon).
Arriving past 8pm is possible, but in our case the SMS with instructions (sent 2x allegedly) never arrived though I was called on my (non German) cell phone to check what time we would arrive (so this is again good). Finally we had to call the emergency number on-site to get the instructions, where the other person really was not friendly, as if it was our fault we hadn't received the SMS.
(For the above two issues I checked "staff" as "bad". The cleaning personnel available is friendly though.)
No elevator (46-something stairs to go for us).
Could use a bigger table and a couple of (even cheap) comfort chairs (instead of the poor single plastic one) in the (otherwise big empty) room.
Location if you want to go and eat (or buy) something nearby: there is no restaurant or grocery store in walking distance (that we saw).
The kitchen (though a microwave is only available in the kitchen on the
ground floor?? Should be easy to "fix" that). The
"shared" bathrooms were pretty much always free, and we could
use two of them in parallel; if you have a private bathroom, you might
have to wait for your partner as your lives are happening in sync...
Wlan was good (connection, speed), but you need to beg for another
(free) ticket at the reception, which is only seldomly manned... Free
parking (though this is just a free public parking on the street). Rooms
are big and clean.