I would say this is a controversial topic.
While some of the changes are improvements, others feel like quickfixes that broke the overall balance of the game even more.
Starting combat two steps apart - not so good sometimes.
Hero skill trees are now predetermined, but some choices are clearly inferior (Potential), sometimes you must pick weak skills to get the good ones later, and the five specializations are imbalanced.
Encumberance was removed, but some items now make little sense (backpacks that make you faster?)
Some spells scale poorly, some not at all.
Combat changes (impalling through multiple armies, etc) are pretty wierd.
Many weak aspects of the game (Tactical combat) were not properly addressed, according to some players.
Please understand that some players are extatic about LH, some not so much (me), so you must decide for yourself. It's not so clear "must have", as some people paint it here.