I've just been comparing a Krait build to my actual Python build. Manoeuvrability wise, 1-2° difference, Python has better roll, Krait better pitch.
Python carries 230 t compared to 148 t of Krait, but it has shorter jump when fully laden, some 2.5 ly. 88 t is a big difference for mission running and mining.
Speed wise, Krait is slightly faster, some 20-30 m/s both normal and in boost, not that big of a difference.
Python has better armour and shield, but no SLF.
All in all, I find Python a better choice. Mine can run large missions and still beat NPC interdictors, 5xMC eat deadly Anacondas really quickly.
And if I need a combat ship, I'd always go with a dedicated ship, in my case a hybrid-tank FAS.
Plus, I don't like that overhang above the Krait's cockpit.