Depend area, mostly they use unifi infra.

More or less yes it'll be the same. Maxis got 2 type of internet, by default they will give you private IP type, which means ur internet will be connected to maxis proxy all the time. Second is public IP which is very similar to unifi, without connected to any proxy, but you need call to request it, its free of charge.

There is a lot factor which can cause internet lag/slow. Mostly hardware faulty on TM side, but they never will replace if there is no serious damage on the hardware. Mostly restart hub/switch/server on TM side will solve the issue but they never will restart it, that cause a lot headache to user like me. If too many house/user complaint it, that time they will just restart everything on their side. Don't forget, similar to Maxis too, they also got their own hardware and server side.

And remember this, there is no perfect thing in the world.