Out of these two cartridges which would you choose?

I have both carts too. That is a hard choice indeed. I cannot sway you to one or the other.

I would, however, say if listen to more acoustic music, folk, blues, and smaller jazz groups I'd go with the Dynavector 20XH.  The Ortofon 2M Black is fantastic though.  It's really great just giving you a macro view--a comprehensive picture.  It can really rock.  The 2M's weakenss, if any at the price point, would be micro details; it does not unearth as much detail as the Dynavector--at least in my system.  All of that said, you cannot go wrong with either cart.  

Both of these cartridges did something similar for me--they opened my eyes to how vinyl can really best digital.  They made me more curious about other cartridges more than any other piece of gear has--save for me moving up to a really decent phono preamp.  

If VTA is of concern you could get an adjuster ring from Origin Live for your arm.  If your VTA is close to parallel you, arguably, won't be damaging your records.  Maybe others could chime in on that issue.  I would think the VTA would have to be high or low with some significant error to cause damage.  If it's high, the stylus would be physically digging down too hard in a forward manner into the groove.  

I'm very happy with both cartridges and feel they offer a great deal of value for the money.