Well, I would love to use something other, but relic made sure when you do, you automatically lose due to potency of allied AT or chinesium armor in case of 250s.
How a 250 which does no damage, 1 PG and 1 PP are supposed to win against 2 rifles and scout without rifles literally suiciding across no cover?
Not a great sample size I know, but recently I've watched three back to back top 20 2v2s and this whole "go Flakvierling or lose" or "DAK is awful to play" sentiment doesn't seem to be completely true. IIRC only one match featured the Flakvierling, and instead I saw a lot of upgunned 250s and even an italian call-in tank you claimed to be "nerfed to death".
Can highly recommend watching btw for anyone who got spare time, very entertaining watch:
https://www.twitch.tv/videos/2168504073?t=04h18m22s