Reuniclus is a staller only in a general sense. :P How would I know? I don't look at the teams of everyone in the first 50. XP Although I've heard some fun stories of Ninjask, I don't ask a lot of people their ratings either. :P I had walls. They couldn't break the Sub was the problem. ;P I threw my team together in 5 minutes and lost probably around 3/4 of my battles. I'd say I don't have skill, and I'd say you do. As for the ofc no stallbreaker=raped by stall, your post suggested that in BW you don't need stallbreakers. Although I haven't played Gen 4 much, since I arrived in competitive battling rather late, I still think you're overstating BW's flaws. I'm not gonna argue which is better, just saying that some of your points seem a little unreasonable.
Gen 4 just because I'm used to it. Very new to Gen 5, and played it a lot with my friends. I loved Trick Room and Explosion. That really made Gen 4 for me.
I don't know what it is, but I find gen 4 ou frustrating. Gen 5 ou is fucking unbearable, as it really is a power>skill game. Instant sweeps with kingdra/exca/cloy. ADV ou is pretty fun I find, it's nice for a change of pace. GSC ou is probably the most "Tactical" gen, it's a shame people who don't have a clue how to play it dismiss it as a "Stall gen" just because a match doesn't end in 30 turns. The same people that use suicune/skarm/kou/tank on the same team. It's a stall gen if you want it to be. Use a drumlax sometime and tell me it's all stall. Anyways, I've always found the lower tiers in every gen except ADV to be the most fun. There isn't really anything that can demolish a team instantly like kingdra. Weather sweepers come close, but most are beatable with some team preparation. It'll be short as hell game though.
4th gen was good for a while and that was during the DP time. DP people were more creative with teams, however once Platinum came into play people just started abusing Sandstorm teams more since scizor got bullet punch after that teams begun to get more repetitive. Latias became OU and people started building most teams around it and as a counter people started using scarf tyranitar with pursuit or crunch. After latias went back into Ubers people just started once again abusing Sandstorm teams with the new twist of scarf ttar late game sweeping, occasionally you would see something you didn't before. The 4th gen Metagame became more about predicting then anything since most of the time you would battle something similar to your team with a few twists. All in all we needed the change to 5th gen to end the repetitive pattern.
Ok I admit Heatran did centralise a bit.. but it's not as if it was a pain to counter. Let's consider broken mole. We have to carry Skarm, Gliscor or Slowbro just to counter it. While I don't remember much trouble with Heatran. People complained about it being everywhere, but not once has someone said it is trouble
Heatran is, in my opinion, the most overrated pokemon in Gen 4. I don't know maybe it's just me, but when I use it, it never does anything great. Kinda like Ferrothorn in Gen 5.
Anti leads became really popular for offensive teams and Heatran is the best option for setting up stealth rocks. Also Heatran has a huge variety of viable sets so it can pretty much be used on any style of team, from pure stall to pure offence including everything in-between.
Yeah, I think what makes Heatran so popular is its utility. IMO, Heatran's high usage is not a result of its ability to fill one specific role, but rather its ability to fill several roles on many different types of teams.
I definitely enjoyed D/P/Pt OU most, but I'm not sure on being the "best" tier. I guess it all comes down to preference, though. The only thing I don't like about D/P/Pt OU is that after Salamence got banned, the same 15 Pokemon is kept on being used on the ladder. I admit I'm guilty of that, too.
Where do you play ADV? GSC is the most balanced metagame, but people are told that it's 1000 turns stall. Then they make a stall team to try out the meta, face other players with a similar team and the same concept in mind, the battle lasts 300+ turns where both players are worthless vs each other and they finally conclude that GSC is all about stalling. Also, I don't know why most people say that less viable pokemon make a meta worse, it's probably the opposite.