is it worth having done? Mine is GX 2.0

Myself I wouldn't bother you would need a few supporting mods and the remap and a lot spend to maybe see 50BHP increase. But on the same note it's your car and money :D  

the initial map for your standard car is biased towards emissions at certain revs and a degree of economy to make the MPG figures quoted realistic - it will be a compromise

 

so if you put on an induction kit and a free flowing exhaust + ensure your injectors are clean, car serviced with good plugs etc I would personally go for a remap - not for outright power but I found in the past with NA engines better drive in low to midrange because the engine is being fuelled at its optimum not for emissions

Also if you run the Vpower type fuel as well it is good to have a map matched to that and get the benefit

I've remapped na cars before , not worth it really as you can only alter a few things and get 3-5bhp