Yes and no. There's been some great changes (HSR and more maps, 'mechs, and Conquest are among the top ones), but there's also been some really bad ones (missile code still broken, heat system's failings becoming very apparent with the high-heat alpha game-play we're seeing, weapon balance is way out of whack, ECM implemented as an amalgamation of four different pieces of equipment, Seismic, ... and a few more).
All in all, the game is - to me, as a primarily light and medium pilot - frequently terribly frustrating. The matchmaker seems to be on vacation, and I'm often the only 'mech under 70 tons on both teams.
But in the middle of all that is a great core game that's perfectly salvageable; but they need to take a step back, re-read some of their dev blogs (especially dev blog 4), and do some difficult and unpopular changes.
I outlined my proposal in
this post in the Gameplay Update feedback thread, basically it boils down to two things:
1. Halve the heat cap and double heat dissipation
2. Rework all ballistics to fire in bursts of about 1 second (and rework the PPC as the beam weapon it should be).
This lowers alpha capacity but increases the value of sustained fire, and it removes pin-point damage completely, adding an additional skill requirement to manage to put all your damage on target when ballistics also spread their damage over 1 second like the energy weapons (and missiles due to spread).