As others have said, it depends on how far down the rabbit hole you want to go with adding details.
Also how do you want to balance build-ability with detail.
Hull fit
The Tamiya kit with it's one piece lower hull and one piece upper adds only the fenders.
The DML kit has a multi-part lower hull and that makes aligning the upper more tricky.
The AFV Club hood and fenders fit is sloppy and takes even more care, at least in the initial releases.
I have built several of each, and the Tamiya hull is the only one I have not had trouble with.
Interior
The interior details of the DML and AFV kits are worlds better than the Tamiya. The visors especially stand out on the DML and AFV kits as being very visible and better detailed.
DML comes with decals for the guages, AFV I dont think did and I know Tamiya did not.
For what it is worth, Archer does GREAT transfers for the gauges and metal data plates.
Tracks
Tamiya one piece rubber bands
DML I am trying to remember if these have the separate track pads like the 250 series, I seem to think that's what I remember
AFV individual link tracks.
Running gear and lower hull
Tamiya is simplified and missing some (barely visable) linkages
DML and AFV have a more complete, but more fiddly assembly.
the Missing links 251 tweeks list
http://missinglinks2.tripod.com/251.pdfMike