While I do enjoy 5th ed, I definitely still have a soft-spot for 2nd edition (and even
RT before it).
I definitely agree with Augustus on Overwatch. I rarely ever saw "Overwatch battles" in the various locations I used to play.
Also, once a player was familair with 2nd, I rarely saw 2nd ed games taking longer than 5th edition games do today. 2 hours for a 1500 point game in either system was/is pretty easy, in my experience.
The "great equalizer" for 'ultra powerful characters' was the Vortex Grenade. It was as if
GW was allowing players to somewhat police themselves. I almost ALWAYS brought a Vortex grenade, but only used it in rare circumstances where I felt I was being 'cheesed' by my opponent - or if/when they used a Vortex Grenade against me first.

Because of this, my group-mates rarely ever brought 'decked-out super characters' to the table, because they knew that in a heartbeat, they could be gone.
That being said, I HATE insta-kill/no save weapons.
GW then eventually brought out the 'Vortex Detonator' to help protect against them. Pretty funny stuff.
That's about it. I definitely can think of more positives about 2nd than I can negatives. Then again, that could just be time/age having an effect.
I do find it interesting that what one person enjoys, another person hates, and so on. Very interesting reading.