An extended range is cheaper than a tanker and some armor, and still packs a halfdecent punch too. Human ERs are especially invaluable (maybe Zuul too) because before AM engines and N-Pathing, only they can traverse the odd 20-something LY nodelines that appear on the map at times. Of course, for SOME races the tanker+extras way is preferable. The Morrigi travel faster in packs, so the standard explorer kit is two tankers, four droneships, four colonizers, gravboat, CnC if available. Laser drones can even kill off a Swarm nest in that setup. The Hivers don't need ER at all when they get Ramscoops, and before that almost any trip to another star is an expedition unto itself - you don't send just a "strike fleet" over STL, you send an armored convoy with a gate ship or two. For others, the ER is the standard scout, no more no less. The sort of ship you send to map the stars out in the early game and forget entirely about until they're eaten by Von Neumann or something.
Also, tried that Dreaded COL thing. Can't post screens - they turned out garbled, maybe because I play widescreen. Anyway, it was rather less intimidating than I expected. With just Leap Mines, the COLs were a lot like guided cluster buckshot. One round is enough to decapitate a Human cruiser, but overall they're not effective, perhaps because the Leaps tend to stay together after release. Researching Implosion mines now (well, Gravity mines. Let's hope I get Implosion), they're 15 per round for a total of 60 per recharge, but their effects should be rather more pronounced. I'll also make a test Flock dread and see if blasts of expendable drones are better than the discrete option.
By the way, if you don't mind micromanaging, standard Flock COL Cruisers can be a rather devastating weapon. Since the COL can be fired manually and fires along the ship's axis, you can fire it ahead of yourself while fleeing - and still have the drones double back and give the pursuers the well-deserved pounding. Add in some quality shields and phaser PD, and you've got the coward's ultimate weapon. Whether or not it was intended, but Morrigi cruisers are especially suited to that one, having a narrow-arc Heavy Turret, facing backward, on their AM engine section.
(well, I guess a fleeing Minelayer can be a bit of a nuisance as well, but the drone COL is less predictable)