At least U Mobile is using more common LTE bands unlike UniFi Mobile which not all devices support.

Coverage issue?

I have no issue using it with iPad, so should be OK. Get a free SIM to try first before committing to it, you have nothing to lose anyway with free SIM.

So far mixed feedback. Some said better, some said worse. Best is to try out yourself because location matters.

That's true, Umobile coverage is really shit.

When one assess coverage, it shouldn't actually be the location of the 4G coverage, but what happens if there is no 4G coverage, i.e. the "fallback line".

When unifi mobile 4G has no coverage, it falls back to 3G tapping on the celcom network. Celcom 3G has a pretty large coverage, and surfing speed is ok for the usual apps like whatsapp, emails, etc.

When Umobile 4G has no coverage, it falls back on the Maxis 2G network. Which is very shitty, you can't even open a simple email with that.

That's my experience with Umobile, and why I have switched to unifi mobile