Basically I can't afford either yet but should have the credits to buy one and fit it out within the week. Plus, this will only be my third ship. Sidewinder, currently in a cobra mkIII and then one of these two.
Ouch...
My ship progression was something like this: sidewinder, cobra mk3, AspX, Krait Mk2, Python... and then Cutter and other 30 ships
Doing mostly supply/delivery missions in early game and mostly passengers with some supply/delivery at Python level.
I started combat with the Krait Mk2, but going in a CZ with it before engineers was quite frustrating. Every time SpecOps Wing came in i had to bail out ASAP.
Haz Res zones were slightly more accessible, until you somehow engage a wing of 3 ships... then bail out again...
So my advise is not to get a krait/python unless you have about 3 times credits their price tag. Running in a non-engineered D-rated ship is kinda suicidal for most of the combat types.
And if you stack supply/delivery missions, do not submit to interdictions - basically avoid combat at all