The DK 48 is very light, it is necessary to hold it with one hand while the other hand take the phone.
The DK 48 comes with 4 adapters:
No. 45 A for the Z3 naked thickness 7.5 mm
No. 45 B for the Z3 with 8.3 mm thickness cover
No. 34 A for the compact 8.5 mm thick bare Z3
No. 34 B for compact Z3 with 9.4 mm thickness cover
The adapter without support allows to a phone 15.7 mm.
The cover must be very thin to be compatible, 0.9 mm in thickness in total!
My compact Z3 is 11.23 mm thick silicone gel in its shell.
To my knowledge the only difference between the different docks or DK3x DK4x is the thickness adapters
DK30 for Z Ultra
DK31 for Z1
DK32 for compact Z1
DK36 for Z2
DK48 for Z3 and Z3 compact.
As against the dk26 to a totally different connection, it is reserved to the first Xperia Z