Gap in between levels and next set, yea, but I almost never found a drop that filled the gap, since presumably for witcher gear the base values were comparatively high for the level prereq. The upgrade also inherits runes, so no waste in popping a max rune in. I see your point if you really need 3 runes of multipliers for something.
I used light armor all the way. Quen was enough to cover my derps. Though as I understand it there are basically unkillable adrenaline face tank builds you can do.
Found something Relic gear is generally better than Witcher gear is:
status effects.
Freeze, for instance, is REALLY powerful. I should note im focusing on a fast attacking build, but still. I managed to grab a +3% freeze silver weapon. With 3 slots. So i popped 3 of the +3% runes in it, and now have +12% freeze on it. Freeze is REALLY powerful. It's like an Yrden sign, only boosted to like 250%. Enemies can't do shit when they're frozen, and it lasts a LONG time, AND it doesn't go away when you hit em like Axii or Stun or Stagger does.
Bottom line meaning, once an enemy gets frozen, they're hosed. It's an over and done battle. Considering how many times you hit an enemy, it's preeetty common that they're going to get frozen, and once they are, it's odds to you that they're going to stay that way. Combined with an upgraded Yrden and Quen signs, mean big enemies mean shit.
Another cool blade i've found is one Relic Steel Sword that gives a whopping 35% bleed chance, 50% critical damage, plus 10% critical chance, and it has 3 slots. So i popped 3 of my 5% bleed chance runes for a total of 50% bleed chance, and now i completely changed my strategy of fighting steel-vulnerable enemies.
I just ping them, bleed them, change target, ping them, bleed em, and, soon enough, they drop. This strategy works even BETTER once i've unlocked the spin attack, that targets multiple enemies. Now, it's not OFTEN you encounter groups of 6+ humans/dwarfs/Scoia'tel
But when you do, it's usually pretty one sided.
AND i've also found another steel blade, that admittedly, does do bit less slashing damage than the other steel swords of that level, BUT, makes it up with +16 fire damage, +10% ignii sign intensity and a 3% chance of burning, and 3 slots, which i've filled with +3% burning runes, for a total of 12% burning chance.
This is MURDER to Lichens, Werewolves, Wolves, & Bears. Why Lichens & Werewolves, if they take less damage from Steel Swords? Because of the pack of wolves they summon when they get under 50% health.
It also works wonders against single or few humanoid opponents, who stop doing everything when they're on fire, including defending themselves, making Burning superior to Stagger & Stun in strictly every way. Freeze is still better, though, and Bleeding still does better damage over a longer period of time.
By comparison, Witcher blades don't carry nearly the same amount of effects. At least until, let's say, about 17 or 18 level or such, i think you're better off with a mix of blades that include at least some of the most powerful relic weapons as well as the Witcher gear.