I rolled another warlock recently just to entertain myself a bit. My first warlock, a level 62 gnome rotting around HFP since TBC launched, was my second toon to get some serious levelling and the first to reach 60, back in the good old days when we played on stone tablets.
I had started the toon before even patch 1.6 fixed some of the most glaring flaws the class came with after the game went live – a time of prehistorical bliss where nobody would claim that they were OP (imagine that! It was shammies who had the reputation of being king of the Power Hill back then. How things change…) but at least fear wouldn’t break whenever you so much as sneezed at your opponent. Stunlocking was already the same PITA than it is today, though (on a side note, I wonder why people keep complaining about the loss of control with fear and keep the mechanism getting nerfed more and more yet the one other loss of character which can get you from full health to death in less than 10 seconds has never been touched).
The biggest change from back then is the knowledge I have of the class and its possibilities, though. Previously I used to carefully pick one target after the other, DoT and bolt, and later on drain tank each in a row. It was fast, more so after patch 1.6, but it there was already so much potential…
Today, I can fulfill that potential with 3 years of knowledge to back me up. DoT up one mob to the max, bolt a second one, DoT and fear a third one, then rince and repeat: Back in the day I never realized I could be doing mass extermination instead of one-to-one methodical cleansing.