Also from your link:
"The He 219 V1 (first prototype) made its maiden flight on 15 November 1942, and demonstrated outstanding handling and performance. The only real problem was poor yaw/roll stability, rectified in the third aircraft by enlarging the tail and extending the rear fuselage. There then began a process of development and tinkering with the armament and equipment that became so complex that today it is impossible to unravel. Even during the war, the RLM (air ministry) asked whether the profusion of types and designations could be simplified. The prototypes flew with a recorded 29 different variations of armament, while the plans for a manufacturing programme were thrown into disarray by repeated air raids on Rostock in March and April 1942, which twice destroyed virtually all the He 219 drawings. These attacks prompted Heinkel to plan for production at Vienna-Schwechat, fuselages being supplied from Mielec in Poland; continued bitter opposition, led by Generalfeldmarschall Erhard Milch, repeatedly delayed any production of what any impartial observer must have concluded was an outstanding aircraft."
"So, how does one assess this controversial aircraft? There is no doubt it was a 1940 design of exceptional merit which could in a more ordered society have been developed for many roles with telling effect, as was the UK's Mosquito. The mass of sub-types merely diluted the main production effort, and the consistent failure of Daimler-Benz and Junkers to deliver the hoped for engines killed the advanced versions that would have kept the He 219 in front. As for the aircraft itself opinions are divided."
"The main trouble was that, despite having an assembly line at Schwechat, another about to start deliveries at Marienehe and a third being set up at the vast plant at Oranienburg (on tapering off of He 111 production), Heinkel's huge network of plants simply could not deliver He 219s. This was partly because of the fantastic profusion of sub-variants, many of them launched to meet official criticisms."
The pilots seemed to have liked it and the major problem was that it was modified too much and packed with too much gear that proved unnecessary. Indeed much of that was only added due to official criticisms that were aimed at sabotaging the aircraft due to Milch's vendetta against the project.
As you highlighted:
"This marginal performance is the more remarkable when it is remembered that the DB 603 was the largest of the inverted V-12 engines used by the Luftwaffe, with a cubic capacity 65 per cent greater than that of the Merlin. The problem lay squarely in the growth of systems and equipment with which the Uhu was packed, so that a typical He 219A-7 version weighed more empty than any Ju 88 night-fighter, and more than a fully-loaded Mosquito."
A list off all the production versions, mostly night fighter varieties:
He 219 V1/V2, He 219 V3-V6, He 219A-0, He 219A-1, He 219A-2, He 219A-3, He 219A-4, He 219A-5, He 219A-6, He 219A-7, He 219B, He 219C/C-1/C-2, He 319, He 419, Hü 211.
that is a hell of a lot for a production run of only 263