First I will see how the Torpedo Slim and the Depth Charge do then I will decide about a Depth Charge Slim. The one thing about a slim on the Depth Charge is it would not hold much fluid probably 1ml on an xl carto sized one.
This would still be worth it Jonah.
1) An extra 1ml is plenty enough to keep a dual-coil (or other carto) nice & wet for continuous hits and consistency.
2) Refilling a DC Depth Tank will be far easier & quicker than refilling a carto. You just...poof...drip 1ml into the tank...done.
3) The slim form factor is a welcome trade-off for those who really want or need compactness & stealth in a sleek design...ie: it doesn't get any more compact than an atty, which only holds 2-4 drops, yet we do it anyway because for many of us its sheer performance and simplicity significantly outweighs its limitation to hold more fluid.
4) Instead of marketing it as a "tank" per se, why not just market it for what it is? It's that extra Depth needed to enhance carto performance and maintain consistency with eeeeeasy refills...just "drip" a whole ml into it and go. Plus, keeping a carto wet (especially a dual-coil) significantly helps to prevent filler-burns and prolong carto-life.
5) Think of the alternative: constantly topping off a dual-coil is a pain in the azz because the fluid has to soak into the filler to keep adding drops. I for one would rather drip into my atty and get great hits right away. I like the first several hits of a dual coil, but soon after it starts to peter out, it doesn't take long to remind me that DC's perform best and keep performing consistently in a DC tank system. I don't even care much for those little 0.8-1.2ml so-called "tanks" out there. Compared to dripping or filling a Torpedo or DC tank, they're a pain to use as well...and some of them look like a prosthetic and have crappy tips that prevent the use of your favorite drip-tips.
I'd get a Depth Charge Slim just for the performance and consistency alone. The slim form factor is an added plus for going out and about and traveling light. And the fact that Jonah makes such awesome lookin' tanks that are also eeeeeeasy to use and fill, to me it's a must-have.