Wastegate Spring or Manual Boost Controller??

So...the wastegate is a Tial 38mm. It currently has a .5 bar spring in it. I intend on having the car tuned to what the 98 ECU will support, 14.7psi and won't be changing it (always this boost). Would I be better off purchasing a manual controller to have the car tuned at this boost level? Or would I be better off opening up the wastegate and changing the spring out to a .9 or 1 bar spring? The previous owner of the kit saw a little bit of creep (about a pound) with the .6 bar spring that it came with...so this made me think maybe an actual controller would provide more consistent boost level. Which option will be more consistent as far as keeping the boost the same level all the time?



