The question one needs to ask is why do you want/feel the need to fit a boost controller in the first place...
MBC's are pretty crappy to use on thier own as part throttle boost control is fairly non existent... only time you may need to use an MBC in parallel with the N75 is to control boost spikes or if in rare cases you have a pikey map that has all the boost request in the world and you are trying to prevent your engine from eating itself without going to the expense of a map thats better suited
EBC's are ok but suffer the same issues under part throttle but can work well (in Prawns case for example) when the mapping is sorted to take advantage of it... it will allow him to control the boost up to its maximum request which is useful on a track car like his...
Using one to get more boost without having a map will just end in limp mode at best....
sorry for the late reply but thanks for the info, the reason i was looking to fitting it was my friend just upgraded to an electronic controler and gave me his old manual one and im not the sort of person that turns down new shiny bits! so thought id give it a go if it gives a little extra boost. Basically your saying its not worth bothering with then?