Elbeem simulation in 2.80 is pretty old.
It was made with the idea to produce simulations on a table, to pour a liquid in a glass, a cup in a plate.
But if you want to make a simulation of several meter, filling a room with liquid : it does not looks realistic because the smallest splash is always too much blobby.
When elbeem was created, it was not possible to make those kind of simulations to go as high in resolution that is possible, now. So, at high resolution, elbeem simulation has issues. You can see steps appearing into simulation due to a lack of internal particles.
Elbeem does not work with force fields.
Mantaflow brings a more coherent simulation according to its size.
It lets to user control on internal FLIP particles of simulation. It uses less particles to produce same effect. For an equivalent quality, baking of test of simulation is done faster. Or for same time of baking, simulation has an higher quality.
It takes Force Fields into account.
It gives more control on secondary particles (foam, spray, bubbles) that are more realistic, too.
You can use a guide to influence simulation. This guide can be a moving mesh or it can be another simulation.
That means that a smoke simulation can influence a liquid one and reciprocal is also true.
You can export your blender scene into a mantaflow script that could be used by a farm using mantaflow to create a massive simulation.
For liquid simulations, there is no discussion. Mantaflow is a lot better than Elbeem.
Some people may prefer to use an external solutionn like FLIP Fluids addon. It does not change the fact that Mantaflow is better than current simulation.
For smoke simulation, Mantaflow just has better turbulence, an animated noise, better border collisions abilities and guiding. Except that, it should restore exact same features as current smoke simulation.
All these additions are making interface of Fluid modifier more complicated. People will have to learn this new stuff because it will replace the old one.
So, people will complain but after providing some presets and tutorials, frustration should disappear.
2.81 is not there, yet. 2.82 will not be there before several months.
So, there is time to polish mantaflow if problems are encountered.
To learn more about mantaflow, you can read thread dedicated to it.
When it will be merged into master, a page will probably be created into 2.82 release notes.
https://wiki.blender.org/wiki/Reference/Release_Notes/2.82