I have not tried one but I am wanting to. But I don't which ones are quality and preserve reliabilty and inspection passablity. I would like to hear sucess stories and failures as well.
I still have original ecu with a Nistune board fitted into it,this was done in feb just gone,i am impressed with the remap ,up to now no problems,it cost £640 fitted etc ,i dont know how this would compare with a new ecu price wise.
on the plus it has 4 times the adjustment of the apexi power fc and allows switchable maps for different fuels There are also quite a lot of plug ins available Like launch control
On the minus side you need an hks dongle to map it.
I think i would go for a link g4 or maybe a motec if i was doing it again.