Missions & Complexes

Yes. Damage-specific drones are far superior than Hobgoblins for everything.

Awesome - thanks. I'll slowly go through my saved fits and modify them to contain the correct drones.

Here's hoping there's no bug in the load / save fitting, and that drones are easily swapped once I have the fit saved. :)

nope, way too lazy. hobgobs or hornets for pretty much everything. Also my blitz list is short enough at this point I almost completely avoid missions with frigs. I also occasionally drop wardens to hit stuff at 50-60km.

if I were running a drone boat then maybe it would be worth changing.

Usually Drones on a BS for PvE aren't relevant at all in terms of Damage. Your main weapon system does all the Damage. I use only small Drones to hit Frigs if necessary and most BS have enough Drone Bay to use at least 2x full sets.
1x Set Warrior II
1x Set Hobgoblin II
fill in the rest of the bay with extra Drones to replace lost ones.

On a Drone Boat of course you have to fill up the Bay with specific Drones.

http://wiki.eveuniversity.org/NPC_Damage_Types

If you look at the table half way down that page, you'll see that Thermal is the most common NPC primary or secondary damage weakness, with Kinetic being the second most common damage weakness. EM and Explosive barely rate a mention in comparison.

If you want to be able to switch drones to suit the damage hole of NPC's, just Gallente drones would leave some gaps in terms of NPC's that aren't weak to Thermal damage, but either Gallente (Thermal) or Caldari (Kinetic) drones would be able to hit either the primary or secondary damage weakness of almost every NPC faction you'll expect to fight.

As well as the regular combat drones there are "Augmented" drones for each main empire which do two types of damage at the same time. Arthur Aihaken mentioned them already. The Gallente augmented drones do a combination of Thermal and Kinetic damage at the same time, mostly Thermal damage with a lower amount of Kinetic damage. Caldari augmented drones also do a combination of kinetic and thermal damage, mostly Kinetic with a lower amount of Thermal. There are augmented versions of all the main empire light, medium and heavy drones. There are no augmented sentry drones.

I'm not 100% certain but I believe that augmented drones come from the LP stores of faction warfare NPC corps, they are going to be more expensive than regular combat drones but either the Galente or Caldari augmented drones are going to be the closest you can get to a "universal" drone that would work reasonably well against any NPC faction.

There are also Gecko drones that do all four damage types at the same time and in equal amounts, but they only come in one size, twice the size and twice the bandwidth of a heavy drone, and there is no regular supply of new Geckos being added to the game as far as I know.

If price is a limitation, buy some regular Gallente and Caldri drones of the appropriate sizes and use each type as required for different NPC factions. If price is less of a limitation, buy augmented Gallente or Caldari drones of the appropriate size and you can use the same drones against any NPC faction. If you are going to be fighting mostly big stuff like NPC battleships and capitals (NPC Carriers and Titans that turn up as rats in nullsec are a real thing now), you might be able to put some Geckos to good use.

I run Gallente drones first. If I have room I'll carry Caldari for use on Angels & Guristas.

I came to that decision by looking at the average resist profile for all the pirate factions. I found that a Hobgoblin, doing the most raw damage of all the drones, did basically the same damage as an Acolyte, which was in the best resist hole, but did less raw damage. Against all factions except Angels and Guristas I found the Hobgoblin was either the best, or tied for the best damage application. Hornets did 1 DPS more to Angels, and 4 DPS more to Guristas. You would think Warriors for Angels--but they do the least raw damage to the best resist hole. Hornets end up doing the same DPS as Warriors because they do more damage to a slightly stronger resist.

You can just use Gallente drones and you won't be screwing yourself; it's always going to be either the best drone, or a close second.

When I use Sentries I almost always use Wardens for the range.

Indeed. I've done a tone of Angel missions over the last year or so, and (based on this thread) I recently swapped out the Hobs for Warriors. Indeed, the frigate killing was slower. (Granted, Gallente Drone Spec is at IV and the other specs are at 3, but still, the difference was fairly pronounced.)

^^This. Hobbies on all the things!

This has been my experience as well.
Combine most things being weak to thermal to one degree or another and the higher damage multiplier of the Gallente drones and they have always worked as well or better than anything else.

I do use all 4 sentries and switch depending on range first and damage type second.

Non-elite NPCs will shoot at drones their "size" and larger. So frigates can switch to your lights (though typically they die too fast for this to be noticeable). If there are no frigs/destroyers on the field your light drones are safe. Once cruisers and battlecruisers are gone your mediums are safe. Heavies always have a chance to be targeted.

Elite NPCs can and will switch to your drones regardless of size, especially the elite frigates. Pay attention to if they are red-boxxing you. If they stop, recall your drones till they re-redbox.

As far as against Angels, Warriors are going to do about the same damage as Hornets, with Hobgoblins barely behind them. This doesn't account for tracking speed though; Gallente drones have the worst tracking--but I've never seen them have trouble hitting NPC ships their size.

EDIT: Oh and in my Paladin, I only use drones till the small ships that get under my guns are dead. After that I have Salvage Drones out. :)