there will always be good and bad feedback on most tuners.
for example, i'm quite happy with my haltech which was installed and tuned by GT Auto. but there are people who had bad experiences with them and eventhough i'm their regular customer, i think i'm in no place to dispute whatever their experiences may be.
my advice is to get a few recommended shops and talk to the tuners urself. once ur comfortable with the tuner either as a friend or just through having conversations, then u can go to second base.
just like taking a girl out lah. even if u go around asking ppl about her, would u really be able to know how she is like in real life. get to know the shop and if ur comfortable enough, try lah doing some things on ur car at the said shop.
no workshop/tuner is perfect, most must have some flaws either way.
from what i know, GT Auto, Speed Effect, N1 and a few other shops do tune PFC. how good, depends on who is judging.
another advice is, i would prefer to have installation of performance parts and the ecu with tuning done by the same person/shop. reason why is that the fella can actually do it from scratch and would not waste time doing troubleshooting if parts are incorrectly installed or other problems that may arise from another mech's handy work.
this would then of course give u the ability to tiu the fella if anything goes wrong.
if u put in parts by urself or by a mech and get tuning done by another mech, then the tuner may encounter problems that might be caused by the earlier effort. thus troubleshooting would cost more time and money (that is not the worst part). worse is of course having the engine blown up.
so walk around and jalan2 cari tuner lah.
u can ask gobiz2 or BloodRed if u want to go and talk to Speed Effect. [PIMPIN] can bring u to N1 and myself to GT Auto. but of course, according to our schedules lah coz we're working ppl also. nevertheless, we're happy to help an enthusiast in need.