Killua did a good summary. ill put these changes into words as i remember them.
in the beginning DH was THE class to play. While all melee classes struggled in Act 2 DHs simply smokescreened and died their way through to Act3/4 to be the first to farm the really good items.
EHP? No need, you get oneshotted anyway. Equipment? Blue items, Vendor crap, doesn't matter - all you need is damage and attack speed. with Nether Tentacles hitting two times and the previously mentioned 4sec smoke screen DHs were considered OP, the barbs of the early game if you want^^ And of course the forums were full of "NERF DH PLX".
both of these skills got nerfed quite fast and the Legacy Natalyas set which provided two discipline regeneration per second became popular. it was the time of pure elite farming, you basically vaulted from one elite to another, using Tactical Advantage for additional movement speed. so even though a lot of people thought the DH wouldn't be viable anymore after the nerfs the class continued to be strong at farming.
Skillwise Cluster Arrow with Cluster Bombs was quite popular. At this time there were also a couple Inferno nerfs, so the equipment got a lot better and more people could farm Act3.
Because of the nerfed Smoke Screen DHs had to focus a bit more onto EHP. People switched over to Shadow Power with Gloom as the top defensive skill and were able to take a few hits thanks to the reduced damage output of monsters.
there was also a quite unusual way to play DH. you could proc LoH with Caltrops and Gas Grenades and when equipped defensively (1h xbow + shiled) survive almost everything. More of a funbuild but still a very strong tank. Needless to say the proc rate on Gas Grenade got lowered and Caltrops couldnt proc LoH anymore at all. But thats more on a side note, the mainstream DH didnt play that way.
then came..i think it was 1.0.4. the one patch i remember which enabled me to farm Act3 relatively safe and fast. Subjectively the patch, that nerfed Inferno the most. After that speedfarming became the way to go. Hungering Arrow "Spray of Teeth" coupled with "Ball Lightning" was a very popular spec. People also played with Multishot instead of Ball Lightning.
For a short time Vault with Trail of Cinders was extremely powerful, you would constantly vault back and forth against elites but apparently the weapon damage modifier was an error..aand it got nerfed/fixed.
it was really "speedy" at that time^^ Vaulting as fast as you can, as many kills as possible - fun times. The Paragon System got released and speedfarming on MP0 or 1 was still the way to go. Now it was all about getting the fastest Alkaizer runs possible. I even recorded my runs to look where i could improve.. A popular build at this time was also Strafe with Fan of Knives for elites. Possibly the most efficient build for MP0 and even though legendaries got upgraded legacy nats was still the way to go. Everything looked good, we were fast, we were agile and melted monsters with multiple good builds.
But the prices of all those shiny new legendaries dropped rapidly. After a while higher MPs beat the old MP0/1 in terms of xp/h because of the lower prices and therefore better equipment. A lot of people dropped Legacy Nats for the new nats and tried to get their hands on a 2 socket Manticore, it was all about high stats for high MPs. Nightstalker was a new must have passive to manage discipline. This was also when I realized, that DHs weren't that good anymore.
You couldn't farm above MP7, MP10 was extremely scary but at least we got the new Echoing Blast rune. Basically the only useful skill on higher MPs. Coupled with Gloom and Nightstalker the once so mobile DH became stationary. Turrets were used, also bola and sometimes grenades. Not much left from the old ranged DH. The forums turned the other way and the first "BUFF DH" threads were created.
After that I got bored with DH (not so much into tanking, theres a reason i chose a ranged class). The whole class evolved now around Echoing Blast and was considered the most expensive and least rewarding. Slowly like every other class DHs moved up the MP ladder but still were behind for example the omnipresent barb or newly buffed WD...
With RF, notably the "Bombardement" rune we got our latest improvement. Snapshotting became popular, breakpoints were found out, the "Fire Support" rune put out impressive single target damage and now there are two viable builds for high MPs. I rebuild my DH, had a lot of fun and even MP10 was no problem at all.
and that's about it. constant nerfs and the change from ranged to melee.
Another strong theme is the way from the op class you had to play to progress to the class you play because you like playing it, the class you put billions into, even though you could build a dozen other characters with that gold. No wonder, that people who play DHs are very passionate about their class.
it's actually the other way around with barbs, who started out as the worst class and rose to become the best class while the fall of the DHs began. Maybe use that to draw parallels in your song.
end of story for me (im from EU, so things like ranged builds or the glass cannon clan had very little impact there. still the moving from ranged glass cannon to speedfarming to facetanking was the same on all servers afaik)
you should watch vids of the different stages of DHs. ill give you a few examples
1.0.2 (Nether Tentacles, Smoke Screen) - http://www.youtube.com/watch?v=rVjDzN0xoV0
Ball Lightning speedfarming - http://www.youtube.com/watch?v=D1Ru77F852E (one of mine, couldnt find a good BL vid :S)
1.0.4 Trail of Cinders - http://www.youtube.com/watch?v=NLEKrygw3FA
1.0.6 Strafe Speedfarming MP0 - http://www.youtube.com/watch?v=K5QtFFFOHeo
€dit some newer vids:
1.0.7 EB - http://www.youtube.com/watch?v=WaRfHomim7w
1.0.8 RF - http://www.youtube.com/watch?v=dgcUBBMpjCk
Edited by memo#2401 on 8/16/2013 2:08 PM PDT