Because it is a fairly recent addition to Hornady's lineup, there is not a great amount of user information that is yet readily available. I have not personally used them, although I shoot the 88 ELDMs, which are fairly close in design. I have found some information about the 90 A-tips, either by diligently searching a number of different shooting forums, or in some cases just coming across it at random.
The Good - from what I can tell, the external ballistics (i.e. the BC and the ability to be tuned to shoot tight groups) of the 90 A-tip are outstanding. It's reported BC values are perhaps even a hair better than pointed 90 VLDs (Berger), and comparable to Sierra's 95 gr SMK. Users in general seemed very pleased with the performance and precision of the 90 A-tips. In my hands, the 88 ELDM also performed very well, with a good combination of high BC and precision. As an F-TR shooter, I have used Berger's 90 VLDs in .223 Rem loads for many years and my opinion is that finding a bullet that will routinely beat the mighty 90 VLD is a very tall order. Nonetheless, Hornady's 88 and 90 gr offerings are right up there in terms of precision and BC.
The Bad - The downside to these Hornady bullets seems to the propensity for jacket failure. I came across several reports where people were regularly shedding jackets of the 90 A-tips in .223 Rem F-TR loads. I personally had the same experience with Hornady's 88 ELDM bullet, having blown up several before I stopped shooting them. The most important thing I can say about that is that if a bullet doesn't reach the target due to jacket failure, the BC, ease of tuning, and precision are meaningless. In fairness, I have also blown up a couple 90 VLDs, but this was from a single specific barrel with a relatively fast twist rate. The Hornady bullets seem to be even more likely to suffer from jacket failure. This is not a new complaint with certain Hornady bullets, as you can readily find yourself via searching. FWIW - I have never been able to cause a jacket failure with either Sierra's 90 gr or 95 gr SMK bullets, even using the barrel that caused the Hornady and Berger bullet jackets to fail. Sierra's jackets are tough as nails.
In any event, there are ways to remediate the potential for jacket failure with any of these heavy and uber-long .224" bullets. Long barrels and the resulting friction are a big part of the problem. In F-TR, 30" barrels are the norm, and that is sufficiently long that problems can arise. A barrel of 24" to 26" length should be less problematic. Second, if you're having a rifle built to shoot these long heavy .224" bullets and want a 30" pipe, go with a 0.219"/0.224" bore groove configuration, rather than the more common 0.218"/0.224". The extra half thousandth on either side can make a big difference, likely by bullet reducing engraving force and depth, as well as friction. Third, go with the minimal twist rate necessary to effectively stabilize these bullets. Usually, a 7-twist is sufficient, if not quite enough to garner the full BC of the bullet. Using a 6.5- or 6.0-twist may net you the full intrinsic BC of these very long .224" bullets, but it also increases the risk of jacket failure.
Another suggestion I would make regarding the Hornady 88 or 90 gr .224" bullets is that they have extremely long bearing surfaces. That means you want a rifle with a very long throat in order to seat them optimally. In fact, they require noticeably greater free-bore than do their counterparts of comparable weight from Berger or Sierra. This can also be remedied in a new build, or by having a new barrel chambered, or possibly having an existing barrel re-throated. My estimate is that going with a 0.219"/0.224" barrel should largely solve the issues related to jacket failure. However, a barrel that is throated optimally for the Hornady 88 and 90 gr bullets will likely only work well with Sierra's 95 gr SMK. The free-bore will likely be too long for other heavy 0.224" bullet offerings that have much shorter base-to-ogive dimensions.
Collectively, the Hornady 88 ELDM 90 gr A-tip, Berger 90 VLD, and Sierra 95 gr SMK are all fairly close in terms of their BCs and relatively precision in tuned loads. Each has their advantages and disadvantages, their little tuning quirks, etc. All can work very effectively in a rifle specifically set up to shoot them. But it will likely require money and time as few, if any, commercial rifles will be set up properly to shoot them optimally.