Post update from GC installation (2022)
As what most of the old timers wrote here, experience with GC is a hit and miss. You will only be able to tell workmanship after a year.
Aircon finally had issues after 1 year, now around 2 year mark. Luckily I bought in on the extended warranty otherwise I need to pay money for the inspection and repair.
GC sent down a team to check on trunking dripping water, particularly at a Z shape turn area. Two blokes came in, open up the trunking, wah water flow straight away on the floor like nobody business. The bloke started swearing in hokkien and started speaking in his mother tongue. Straightaway knew the initial workmanship caused it. Chap was nice and shared with me the issue and cause.
During installation, hard to be overseeing the entire installation without affecting the installer like micro managing, end up they deliver sht work when nobody observe them. The bloke shared the insulation foam used was poorly taped up when at connecting sections plus (bend areas), gaps from one room to another was not covered up with silicone which is a basic, thus leading to condensation causing trunking to drip water. Would have continued to go unknown but thank goodness the silicone wearing off so water could come through, else drip water you also can't see from inside the trunk.
Will choose south asian team going forward, over the neighbours from up north (first installers) in future. They know how to fix the problems and didn't smoke me.
This nice service team also shared based on their experiences, these are the current 4 good brands to go with (less faults), Mitsubishi Starmex, Daikin, Toshiba and Panasonic.
They shared all the other brand like LG, Midea haha

good luck if you choose to be cheap on the initial costs. They also said not just here, back home those 4 brands are also more used frequently.