First, you may want to define what you think a varmint is. Varmints are generally rodents while coyotes, fox, coon etc are predators. What are you wanting to hunt? My experience is predators. But IMO, any of the heavy weight .224 bullets aren't gonna be worth a spit on varmints or predators. Too heavy construction intended for punching paper at long range not putting critters in the ground. Deer are another matter. The lighter BTHP's like the 52 grainers are pretty good on predators. Less blow up on fox but you'll get more exits on coyote than say a 50-55gr V-max.
The heavy weights are a current fad with the target shooter crowd (for good reason) if you want to use a .223 for long range but are not intended for hunting smallish game. While you may find someone out there shooting P-dog or coyotes with em 99.9% of the serious guys are gonna continue to use lightweight bullets. Me included, if I want heavier bullets for hunting I'm not using a .224, it's time to step up.