tuning boxes

hi there folks
Any one had any experience with these diesel tuning chips...trying to persuade a mate not to fit one hes paying about 130 quid for one , ive heard few negs on this so thought ide ask on here ,,maybe a recommended unit that forum folk do use or maybe a def...no dont use.
cheers folks

if its a ron box, they come highly recommended

GrumpyGel said:

https://www.landyzone.co.uk/land-rover/rom-box-what-is-it.299685/

Click to expand...

thanks for link

I have found the best thing is to fill up with this new V Power from shell I can not believe the difference.