Now there is 2 types of players/groups, those who have to work really hard with 5k'ers for few days to put a base and those with barges who can make it in few hours without any sweat only having 2 ships... jumper and the barge, thats not really balanced situation at all.
Its just nearly impossible to rent or buy it even you have credits and thats what pisses the most.
40k too much? make it 10k, 50 cruise speed, 200k hull and no cm, no turrets... whatever, since 99% can't have it, why should they care.
And if you ask those who already have it... well obviously they don't want it raped even more... it is already planetoid size and if not JD Mk4 it would probably get totally corroded in hangars.
Even you have proper technology to move it using JD don't forget you already had to spend lot of credits to buy those ships and equip it... nerfing it even more you will punish those who invested so much to get it working.
Put it on market again or make other ships larger than 5k, other way around is simply unfair for the rest of hard working players due to such unbalanced situation.