I'll try to summarize some of the features, it's mixed but mostly positive.
• Viewport - performance has seen serious improvements with 2017+, however don't install PU1 because there's a regression which will successfully simulate a 1990s era viewport in terms of speed. Solution is to wait for a possible PU2...
• UI - dockable windows, big plus. A modern feel - plus. Some bugs with the render dialog focus, though, which can be very annoying.
• Modeling - Spline Booleans - huge plus, seriously cool to have it finally.
• New Booleans (introduced in.. 2017 I think) - better workflow, an important option to keep edges on flat faces has been added in 2019. It is more stable, too. Still there are a few rare cases where ProBooleans will produce a valid mesh and the New Booleans will fail. But it's definitely good enough for daily production and way more accessible.
• Shading - OSL - seriously cool and work with every renderer that supports max shading contect (Scanline, Vray, Corona etc.)
• Alembic - more interop options are always good.
• Fluids - Naiad-based, good stuff. A few rough edges usability-wise but definitely usable. PU1 brought some improvements... but will cripple your viewports so... wait for a possible PU2, again.
I'd say try it, use it for one, two weeks in production and see how it goes. As usual, it may work fine for some people, others may have issues with certain tools etc. But in general, I think 2019 is finally a worthy successor to our beloved 2016.