The options in the same tier as Conditioning should be drastically improved honestly. Not just one or two extra points of resistance that's going on in the PBE. Like more than twice what they give currently. 5 armor or 6 MR is a fucking pittance at best, and the 5% SOMETIMES increase is a joke compared to the prior 5% bonus to BOTH stats unconditionally with masteries on top of the missing 15 armor and 12 MR from runes.
The new runes are supposed to be stronger than the old masteries because characters have less stats to work with, but under Resolve they're not even AS STRONG as previous masteries.
Mirror Shell and Iron Skin should give 9.5 of their stat up front, and 0.5 of the resistance type each level up, up to 18 of the stat at level 18. This is in line with the 27 armor (counting the additional base 9 armor across most of the cast), or 18 MR, which seems comparable at least since mages are missing their flat Magic Pen reds.
Besides these options meant to be for specific matchups that are completely worthless since waiting 10 minutes passively for Conditioning to kick in is more than worth it, the replacement for Fearless is also abysmal. Second wind is somewhat comparable to fearless's impact against light poke, but substantially weaker against bust, missing out on the 10% and 1.5-9 resistances in the early game against harassment tactics.
There's also the missing Legendary Guardian block, which was the WORSE of the two options in its slot but still granted better stats than anything in the new runes for defenses, granting 3 resistance each against your solo lane opponent, 6 in a duo lane or when ganked top/mid, 9 ganked bot, and 15 in team fights.
The only option in any tree that offers remotely comparable boons is Aftershock, which is proccable only by some characters and for melee users requires getting through ranged harass just to have the CHANCE to proc it.
In addition, there's missing resistances from Siegemaster of course, and the weaker trading power from losing Tough Skin as an option over Siegemaster where it would be a useful tool.
And finally there's the fact that on top of all of the base armor and AD changes, the new runes grant their set bonuses which offer significantly more gold value in AS, AP, or AD than they do from the 130 health