I run an AmD Tuning custom remap with 265bhp, but I have additional modifications to get that power. They are;
Milltek cat-back stainless steel exhaust
Panel filter (K&N)
GFB DV+ diverter valve upgrade
My girlfriend has almost identical mods but only gets 259bhp, which I like reminding her about. The power gain varies with everyengine, my advice is expect 230bhp with just a map and up to 250bhp with mods then you won't be disappointed.
The AmD map, for me, has been perfect for nearly a year and 8000 miles. They have gotten better in recent times, and they're customer service is pretty good.