Lemme summarise my location.
a) Shopping malls - some users mentioned inside building so i tried.
b) KTM and KLIA Express - some users mentioned moving train, so i tried
c) KLIA Express underground and shopping malls basement parking - some users mentioned underground so I tried.
d) some residential areas at my gf condo at damansara perdana and Bukit OUG - some users mentioned residential (including you) so i tried.
e) KTM ETS from Butterworth, Penang, upto KL Sentral.
My results, UM is kinda good at many of those areas. Not bad if you ask me.
Thus for you to say i tested only at malls/lrt/train stations isn't very accurate. This is because i have 2 residential results plus underground plus moving train that goes through jungle (all greens so i think so).
I have not experience any congestion issues like some users mentioned. But coverage, I do agree some places umobile coverage is bad that it enters 2G.
But most of the time, places where normal humans will go at normal hours, the coverage is ok and congestion isn't quite the issue.
To users who experience fluctuation in your line, why not set your phone to LTE/WCDMA for better stability?
Anyway, I agree my test location is too small. There are more areas to test, especially when KL is so big. Wait till i go down next round to find my womAn again, then i'll try setapak and hulu langat too. My bro recommend fish farm restaurant at hulu langat.
From my experience, the congestion issue happens due to location and the locale. Eg. In Ampang, there are lots of low cost flats and housing nearby hence the congestion is quite bad IMO because Umobile is cheap with plenty of data. If you're in a upscale area for eg., then the congestion problem might not hit you due to spread of telco usage & telcos favouring to better equip those area.
Again, this is my 2cents.