If you wear Mad Bomber, you'll only need one Elite Boom to reach Max CTR/Max Damage, which is always nice. You can sport a Penta Heart Trinket in the other slot.

If you want to do some Lockdown, Voltaic Tempest and RSS work well there. Anyone worth killing is going to have Shivermist immunity due to the prevalence of the Skolver set. Voltaic Tempest is also a favorite of mine for Candlestick and Scarlet Fortess since it works great on Kats.

DBB = WINNING in Wolver Dens. Sometimes I'll use it in Devilish Drudge too, or general fiend levels. The slow fuse takes some getting used to and makes it difficult to use on Greavers though. On the plus side, the bomb is not as disruptive as Nitro and knockdown is a lot more useful than knockback, makes chaining easier and won't disrupt fellow swordies.

RSS makes quick work of Zombies/Trojans in FSC, I prefer that over Nitro there. I rarely use it outside of FSC.

Most people would recommend the Electron Vortex over the Graviton line. The damage type/amount is negligible but it has a shock proc which is nice. It only becomes really useful at 5* though, and is best paired with a Brandish charge, either your own or from another party member. See http://forums.spiralknights.com/en/node/21959

Both Volcanic and Bombastic for buffed recently, making them useful and safer alternatives to Mad Bomber. Full Mad Bomber works fine too, of course.

The only thing you really missed out on from the sound of it was the addition of the Dark Retribution and it's IMMENSELY broken speed apart from the armor upgrades, but most of the old stuff would still seem to work pretty well. I mean, sure, the bosses are getting a little too easy and boring right now, but still, it's nice to go out and experiment with what you have to get used to some of the stuff that's been added, in fact, pretty much out of sheer boredom, I went out and killed the bosses, the standard ones, anyway, with only haze bombs. Doesn't take as long to do any of it as you might think it would (anything but vana doesn't even take an hour, and even then he only takes 2) :P Not really a lot of "new tricks" to learn, maybe some new "patterns" to say the least. Since they always seem to be having to fix bugs with boss fights. Matter of fact, add me if you want, we can go do stuff together :D