The DBX never did appeal to me mainly because with a class 5 fuel tank I could only install up to a class 4 fuel scoop. That makes for long refueling times. The Dolphin is nice but exploring I went with an Orca versus a Dolphin which is faster, jumps farther and holds a lot more. Then I installed a class 6 fuel scoop for it's class 5 fuel tank. Fast refuel times especially when doing 400+ jumps.
As for the Dophin I made it a dedicated planetary material collector and especially for High Grade Emissions in USS. Of course it is just for the bubble but a lot of fun to fly!
Here's my
Orca build for your consideration versus the DBX or Dolphin.
3 beam lasers not needed but feel good having them.
Class 5 shield generator for landing on high-G planets.
Heat sinks that I have never used. Still just in case...
Supercruise assist for automatically orbiting a planet (love that).
1 SRV as if I get stuck just logout/login to Non-Horizons to get it back.
Docking computer in case I forget how being in the black for months.
54LY jump is plenty for me. If max jump range is desired a stripped down Orca can easily hit 65LY+ with high limitations on power, thrusters, shields, distributor and sensors. Is it worth it? To each his own desires...
With game experience and good pilot skills the Orca for me is a nice comfortable explorer with no equipment limitations. New to exploring? Try an A-rated low/non-engineered DBX, Dolphin and Orca exploring outside the bubble say up to the 5000LY range to complete the engineering requirement for Professor Palin. Play with all the equipment to be proficient using them. Gain experience on newtron stars (might need a heat sink) and other dangers especially if your ship is destroyed. Less painful versus 60,000LY in the black and quit the game in frustration as some have. Then build your explorer ship knowing exactly what you want and appreciate having it in deep space. The galaxy will still be there when you have the needed skills and ship to explore it.
Meanwhile if serious about technically exploring the galaxy Frontier created you'll appreciate this
Advanced Navigation video. Frontier is serious about the science.
Regards