In contrary to most of the negative review here, my experience with Zero1 is way more acceptable, partly due to the price that I am paying and also the low expectation arises from the negative reviews here.
I do wish to share my experience here, for some of the people who are still keen to try out their competitive plans.
I signed up for port in on the 30 Nov 2018. Receive my delivery confirmation on the 2 Dec 2018 and the earliest delivery time available is on the 6 Dec 2018, but you can only select the time slot from 9am to 6pm, which mean you have to standby for the whole day (Please do take note of that). Alternatively, you may opt for self collection like some other did.
And true enough, I received my sim card on the 6 Dec 2018, 11am. I did use the tracker but it wasn't a real time update. So I was not sure when exactly will it be delivered and I didn't receive any call to confirm if I am available for collection. However, since I will be in the office anyway, it didn't bother me much.
On the 6 Dec 2018, at around 10.44am, I received a sms from Zero1 stating that porting of my existing number is approved. (There were a few more sms before, informing me that the porting process had been initiated etc.). At around 11pm, I lost all my network connectivity from M1 (my previous service provider).
I didn't check constantly, but at 2am, I manage to get some signal from Zero1 sim card, but availability of data, sms and call were only available in stages. I have my data connectivity at 2.15am, and only have my sms and call availability in the morning around 7am.
And so, the porting process was a success and I am grateful that the process is not as bad as some other unfortunates.
Now, for speed test, around commonwealth area, I am getting peak speed of 100Mbps (Mega Bits Per Second) for download, and 80Mbps for upload. The speed will fluctuate but it hover around 70Mbps for download and upload.
After the 1gb data, I am consistently getting 0.7MBps to 1Mbps speed. And truth to be told, streaming youtube at 480p seems fine for me so far.
Customer service wise, like what the other mentioned, you can't expect immediate response (through email or facebook) and there is no hotline so far.
So, in conclusion, if you are someone that can take this kind of uncertainty or you are just looking for a plan for your secondary devices, I think this is a good plan to have.