First of all, this weapon matches Calimacil's standards for wondrous durability and artistic detail for their foam weapons; not much more needs to be said there, as they remain first class in these regards.
As for performance, the doppelsoldner's weight makes swinging it take a lot more effort than most other weapons, so using both hands is extremely important for control (Do Not attempt to wield this monster one-handed, unless you want your shoulder to complain the rest of the day), but it remains just as safe to hit as other Calimacil weapons. The sheer enormity of this thing also allows for more technique than just slashing around. For example, grabbing the wrapped blade below the quillons effectively turns it into a spear, which is actually a historical use for a weapon of this size.
And speaking of size (and history), Calimacil have truly outdone themselves with this weapon. As far as my lengthy searching has found, this is the ONLY historically accurate instance of a foam greatsword on the market (most greatswords historically measured around 60-70 inches, or 5-6 feet, from blade tip to pommel); all other competing brands create longsword-length weapons (stopping around 48-55 inches), but label them greatswords. The amount of effort put into making something so large safe and structurally stable must have been challenging, and so a special thank you goes to the R&D people who figured that out. Of particular note, however, are the rings on the crossguard, which as noted elsewhere, are clearly fragile near the bulbs. Mine haven't broken, but it's clear the point of connection is a bit too small for the kind of abuse the weapon is likely to face through prolonged use.
Overall though, despite what amounts to a single minor flaw, if you're looking for a PROPER greatsword for LARP, this is the absolute best you can find. As of the time of writing this, there is legitimately zero competition for professionally made and historically accurate foam greatswords.