I like Survivalist's general concept of using anything moderately well, my gripes about it are how it falls short on achieving that concept sometimes.
Something to note about Survivalist is that merely having a variety of weapons is actually not a benefit to him over other perks. With one extra click in the shop menu, any perk can buy any weapon. For example, boomsticks were popular with Medics. So Survivalist's variety of weapons specialty is actually only an advantage for him in so far as he gets noticeable benefits applying to multiple weapons in a variety loadout.
Two weapons is very common in loadouts, so Survivalist becomes a pretty underwhelming option if any of his weapons get only negligible benefit, since he'll get only moderate benefits to the other weapon, whereas that weapon's real perk could get great benefits to it. For example, if you want SCAR+RPG, that's a variety loadout, so you should expect Survivalist to be a clear winner for what perk is best to play that loadout as. But instead, by picking Commando or Demo, you can get great benefits to one of the weapons and zero benefits to the other, and this can work out better than picking Survivalist and getting moderate benefits to one of the weapons and minor benefits to the other, depending on your reload skill choice.
That's why the disappointment of reload benefits being split between two conflicting skills is a huge drag for Survivalist. For the half of his weapons he doesn't have quick reloads for, the benefits can be borderline negligible, (+15% damage often rounds down to 0 fewer hits needed.) potentially nullifying a main appeal of playing Survivalist at all.
My main suggestion for Survivalist is to
unify the reload skills, which will make him much more consistent in having a moderate benefit to all weapons.
Another major point is that "Survivalist uses whatever he wants" is not a fully realized concept, there's room for expanding that. Most grenades are unavailable to him, and he's stuck with randomization for his spawn weapon (this especially sucks in combination with the split reload skills, spawning you with a mismatched weapon. [though caulk is even worse]).
I've suggested how full freedom for Survivalist can be implemented here:
https://forums.tripwireinteractive....on-potential-new-survivalist-options.2331041/