These are a descendant of the Trophy Bonded Bearclaw lineage...
I have no first hand experience. However, I strongly suspect they will be awesome. Some bullets expand rapidly (Nosler Ballistic Tips, Hornady SST) however they don't hold together well at high speeds. Some bullets hold together well at high speed (Barnes TTSX, other monolithics) but don't open well as slow speeds...
Recently manufacturers have made some huge improvements in bullets: We now have bullets that will open well at low speed AND hold together well at high speed. I think a lot of this is driven by the long range crowd: That game uses high initial velocity cartridges for the most part (like 300 mags) and drives bullets fast. Its possible to get a short range shot (meaning high impact speed) but often long shots are the norm (low speed impacts). This is a VERY tough set of criteria on bullets...
The monolithic rear half on these bullets combined with the bonded nature of the lead 'front half' is very reminiscent of the BearClaw heritage. This is good to go. Expect deep penetration and a bullet that largely holds together even under high speed impacts. The bonding process often serves to 'soften' and anneal the bullet itself and results in a bullet that will expand at low speeds (which is pretty much how bullets like the Nosler Accubond LR get their low speed expansion). Again, this should work well. Its not really all that new an idea. The hollow polymer tip? I dunno. That IS new. Is it reliable? time will tell....
I'll make what I consider to be a fairly well educated wild assed guess: These will work decently well with regards to expansion at all advertised impact speeds. None of what Federal is doing is all that cutting edge/new. Will they be significantly more accurate? Jury is out on that one. The firearms industry is pretty free with its claims about sub MOA accuracy, most of which is pure snake oil salesmanship. Federal's Trophy Bonded was a decent bullet with modest (mediocre?) accuracy in the limited testing I did. Will this new descendant be significantly better? I dunno...
Here is the big issue: Will all this gee-whiz super-duper bleeding-edge high tech wizardry actually make all that much of a difference? Probably not, at least in most cases. If you are loading 180 grain 308 Win loads in your Remington 700 and shooting whitetails at 128 yards as is often the case, these new $48/box Federal cartridges aren't going to kill deer any deader than the Labor Day Weekend promo $12.99 box of Winchester Power Points or Rem Corlokts. No difference. None. Zip. Nada. The common 20 or 24 inch barreled 308 to 30-06 never really pushes 150's or 180's fast enough to really ever need any sort of bonding in a bullet. The Federal's MIGHT shoot a bit smaller group, but 1.5 Moa versus .5 MOA at 128 yards means the bullet is potentially "off" by a whopping 3/4 of an inch. Your deer is still dead, tagged and freezer wrapped....
If you are shooting a very fast cartridge (3100, 3200 fps MV and up), the bonded nature of these might be useful on a close shot. I shoot 160 Nosler Partitions at an honest 3003 FPS muzzle velocity out of a 280 Ackley Improved. These expand VIOLENTLY up close. Some form of bonding or a partition is a decent idea at these speeds. The bonded nature of the these new Federals means less risk of bullet failure on a shot at 9 yards with your SuperDuper Magnum. On the other hand, if I chose to shoot deer at 600 yards, the ability of these bullets to expand at low speeds means the long range performance of these new federals may be useful.
If you hunt with anything larger than a 6.5mm Creed/260 Rem and smaller than a 30-06 (including all the regular common cartridges like 7mm-08, 270, 280, 308 win etc) these new Federals are totally and absolutely unnecessary. If you want to spend $50 on a box of twenty, have at it. It won't hurt. But you won't see much in terms of improved performance.
If you are shooting a 7mm STW at elk 700 yards on a regular basis, these might be worth the money.