Which 300x300x400 printer?

[curious aardvark]

the short answer is that most upgrades make very little difference and aren't worth doing.
people like doing it, I've yet to work out why :-)

My dirt cheap ctc 13 pro b - has the cheapest, nastiest extruder I've ever seen - it's not even spring tensioned.
I modded it with a couple of short lengths of ptfe tubing and it's a cracking little bit of kit.
First one I've had that will actually print well with filaflex original - and that stuff is like wet spaghetti.

Rather than learn to use the printer they have, people seem to prefer changing things - for no apparent reason - and having problems with the changed bits.

Also it's a new model - so won't have as many owners as older models.

For some reason - again beyong my understanding - people keep buying the machines with the ender 3 design flaws. They are cheap - but you have to factor in, upgrades, mods and time spent banging your head against a brick wall and swearing a lot.

The 3d printing community can be - largely - divided into two basic camps.

1) people who think it's magic and will work perfectly out of the box. They haven't learned to design, they haven't done any research beyond watching a few youtube videos.
2) people who just like to tinker with stuff, whether it's necessary or not. 'the z3000 stepper driver will make my printer 0.002 decibels quieter and under a scanning electron microscope you won't see the fractal patterns any more.'

There's also a small group of us in the middle who buy cheap and do the bare minimum with the existing hardware to actually get it to work and produce practical things.