I also tested Eight for my MRT trip from Boon Lay to Farrer Park (EWL + NEL, change at Outram Park MRT).
In general it is okay, with very slow speed in Chinese Garden only.
But of course it kind of failed the test at City Square Mall B1 level, especially at Jollybee.
I was testing M1 Maxx S$10 plan (5G) for the return trip from Farrer Park to Boon Lay, the speed is of course much faster than Eight.
If just for my usage in Singapore, I will say M1 Maxx S$10 plan is quite a bit better than Eight S$8 4G plan.
But I understand many users here use good ways to reduce the effective monthly pricing of Eight S$8 plan to much lower than that. So that may change the value proposition.
My main Singtel S$15.28 line is still better in terms of consistency than M1 Maxx S$10 plan. I have no intention to change it.
You keep emphasing that you have no intention to sign up a singtel mvno as you already have singtel $15 plan.
I feel you need a more holistic view of everything to be more fair. I suggest if you have time or extra phone, port a line to Zym or Zero1 to test out the 5G NSA against your Singtel Sim Only $15 plan. We also want to know what is the real difference between Singtel $15 and Zym/Zero1 $15. I mean, if there is really a difference, then you can say main $15 singtel line is better.
Try out both Singtel and Zero1 during peak hour at Outram Park, Jurong East.
And also inside mrt trains between Jurong East and Clementi (near Ulu Pandan) and Outram Park to Tiong Bahru.
Don't do speedtest, but do a more realistic test, like general surfing of websites like CNA, Straits Times and streaming CNA Live from youtube. Test out if there are any buffering or lag. Speedtest isn't a good measure for good network.