Hi,
I'm not certain about that, and one thing to remember is that there is always hassles with the newest Cloned Muxes from Chiyaneeseys ................. C5 is only just getting sorted to be as reliable as the C3's and C4's, which were same way back when they first came out
For W220 and Cars up to at least 2017 C4 is fine. C3 only goes to around 2012 Cars model dependent
Older Cars, or Cars with some older tech Modules, like fe my SLK R170 2002 need HHT Win for modules like VR, ATA, PSE etc, (HHT is part of the Software on laptop), and I'm not certain that that HHT even works with a C4 as I have never tried that.
I have 2 machines, (well 3 now when my new 2019 Toughbook one arrives lol), so I always use the C3 with 2014 s/w on that Car and the C4 with my custom 2017 s/w (has no HHT) on late stuff, will be using the Touch Screen Panasonic with my C4 most I expect when it arrives, and hoping it has HHT and hoping HHT works with C4 if so it will then be my go to machine all the time
I will test all that some time in next month when all calms down at Dave2302 world
BTW, HHT stands for Hand Held Tester which is what MB used before they developed SDS DAS.
HHT is an emulated program on SDS Windows, it is incorporated in all the early SDS and on some of the newest but not all.
If I was you I'd go for C4
HTH,