I think everyone is making a valid point. The idea is diversity. You can make an argument for most ships. And, a lot of it comes down to style of play. For npc combat, I arm and engineer my ships for sustained fire. As in, if I'm in my Corvette, I can lay on all seven weapons. As opposed to overpowering beams, and switching in bursts between thermals and kinetic.
I like the Clipper in combat. It's one of the ships I use when I'm "being serious." (haha). It's great for just going through and picking off vipers and vultures and little guys. I use my Clipper, Challenger and Corvette for combat the most. But, most of us have a large storage of weapons and equipment for our ships. I like using my Cutter, Anaconda, Python, Krait, Gunship, even my Courier sometimes in combat. I just don't kick as much ass as the others due to my preference of set up and play. I've actually been using my Anaconda in combat more. I finally figured out how to use shock cannons properly. You can only have one on the ship and pop out a bunch of rounds fast at closer range. I also like ramming, and the conda and vette stop and turn without as much drag as the T-10 or Cutter.
And, even though I use my Dolphin the most for just bouncing around the bubble... the Cobra Mk IV is probably the best overall ship that can land on a small pad.
I think they need more weapon types than more ships. I still argue strongly for a mid-level kinetic. MC - light, Cannon - heavy, give me a medium. Just split fire rate, damage, dps, etc. right down the middle between MC's and cannon at each class. I also think at least class 3 and 4 plasma accelerators should have a gimbal option. They don't fire fast enough, or have enough ammo to over power any ship, and you're going to blow yourself up if you try arm your whole ship with them.