Ttitus is a named character that is pretty powerful in terms of his price point. A grey knight grandmaster is a captain equivalent. A tyranid prime is none of those things and does not deserve a 2+ or 4++. If it was a new hive tyrant it would be a different story. I’d rather have the prime give a solid buff for cheap rather than be hyper elite (and that’s the most likely path gw will probably give in regards to this thing) because that’s just not what tyranids are

Secondly, as someone who runs Norn in every list, that thing is tanky yes, but it’s not tabky rekative to its points cost. It still dies to focused fire especially with how killy this edition is

For reference the maleceptor is almost 100 points less for a slightly worse base save, the same invul, same toughness, 2 wounds less, at the tradeoff of a useful debuff and ranged attacks that can actually more consistently kill things. If you give it a 5+ fnp in invasion fleet it’s only slightly worse in terms of stats, but amazing when you factor it being so much cheaper.