I actually like the Essentials line - a lot. I just think it's sad that it's coming out so late and seems to have upset so many diehard fans.
I only picked up 4e at the beginning of last summer but I fell in love and played in three different campaigns, several hours per week. I had a blast. I especially liked the Character Builder software because it let me make characters, and play around with them, quickly and easily.
I felt somewhat frustrated, though, with a few things:
1- I came in late enough that there were mountains of feats. On top of that, the "expertise feats," (+1 to hit with xxx weapon) were seemingly standard but I didn't know that coming in.
2- I had this one character design stuck in my head the minute I picked up the PHB 1. I wanted to be a Dwarf Fighter that acted as an awesome, amazing tank/defender.
Here's the thing - With PHB 1, Dwarves were actually not optimized very nicely for this role, since they got a + to wis instead of to strength. Plus, the fighter was burdened with tons and tons of at-wills and utility powers, etc.
I picked up the Heroes of the Fallen Lands and, after my first reading, it was like an epiphany. THERE was the character I had wanted to play all along. Dwarves finally got the + str to make them viable fighters, plus the addition of plate off the bat, plus the new marking aura and the stances, plus the way hammers work ...
It was like FINALLY this iconic concept, which I wasn't able to really do with PHB1, was available. WHY wasn't this PHB1?!
Needless to say, I'm extremely happy with Essentials and hopes Wizards keeps up with Essentials for at least the next few years.