Each tech tree ( with the appropriate ideological choices, trait and abilities) does support/accentuate certain playstyles usually based around a particular game mechanic. I have just finished (almost) playing each of the standard factions on suicidal and each time I found it hard to win unless I figured out and embraced the relevant playstyle. Some playstyles are more effective than others and some are simpler to execute. Thalan is a solid choice but when I really want to be OP I use Iconian. The highlights being, a multiplicative social manufacturing bonus early in the tree, food bonuses and a unique logistical bonus with intelligent ships (more ships per fleet means more firepower which means less losses)
Yor is also very strong. Although that is more to do with synthetic population mechanics than anything to with tree itself.
Altairan was surprisingly good mainly because they get neurolinking in the yellow age, whereas everyone else research 100 techs first. Its a nice advantage.
Any tech tree that relies to heavily on influence mechanics is pretty gimped. Influence is very easy to defend against just by building resistance and most of the races you will really be worried about will be malevolent who quickly become immune to influence flipping. That hurts Iridium, Altairan and Krynn primarily. Although Irdium is actually not bad if you go trade focus.
Drengin incentivises you to rush. Not really sure bout Drengin tbh I played them wrong but still managed to win somehow but was pretty ugly game, was far too passive for too long,
You really have to play a few games with each to get a real feel for them and find what suits you. Map size and game setting have a huge influence on what playstyle is optimum. Is there likely to be a lot of room to peacefully expand or are you going to need to start invading, can you effectively play from a small number of planets or do you HAVE to have an expansion advantage, things like that.
Would be interesting to hear if there are many people not on the Thalan hypetrain.
