i didn't mean to imply i don't respect tgm or whatever. i've played tap death, and i agree that it's very hard and demands a very limited scope of options, which the player has to come up with quickly. that's great. i just don't think szsz is as big a deal as we're making it out to be. if you ask me t/j/l are harder to deal with in tgm than s and z. edit: btw, those settings i mentioned playing on heboris lite were with step-reset and one floor kick. srs is much harder than ars without floor kicks.
I guess the reason I notice it more is that when I play TDS I don't lose my TGM habits entirely. I build in a way that anticipates no duplicates, and generally the only time it stings is with SZSZ. I think duplicates help you go faster with a pure randomizer, because you have no expectations about what comes next. But with a "smooth" randomizer, you expect regularity. So duplicates are unexpected and will slow you down. Seriously, I find myself sometimes wanting the same piece twice to fix the screen... and yet if the game actually deals me the second piece quickly I often won't use it effectively because it surprises me. Though that only happens when I'm playing my fastest. You could probably make a good cogsci experiment out of that...
The pre-TGM history came from Mihara's interview in http://www.arika.co.jp/product/tap/inter_tap_02.htm . The default rotation that hugs the floor at least was most probably intentional, as it is a carryover from Sega Tetris 1988. Sega Tetris was the first game ever to feature lock delay, which, combined with ARE, fast DAS, and the ability to charge DAS during ARE, allowed people to keep playing with minimal wrist strain at its top speed of 1G. As the game had no wallkicks back then, the floor-hugging default rotation was a true necessity. Hm, I actually disagree with Jago in that usage is optional, partly because both movement and rotation cause a lock reset. Players can obviously refrain from mashing the rotate button to keep the piece alive, however, resets originating from movement affects all players whether they like it or not. If you place a piece one block off from the intended location, on a flat surface, you're pretty much screwed by the time you notice it in TGM; With move/rotate-reset however, knee-jerk input upon noticing will still register, even with lock reset limits in place. On the topic of floorkicks: floorkicks in SRS should be differentiated from those in TGM rotation, mainly due to SRS requiring certain floorkicks in order to rotate on a plain flat surface. The SRS floorkicks aren't optimized for 20G either, as using floorkicks to rotate a piece on a flat surface will result in the piece nudging to the right/left. Turning off all kicks in SRS 20G will obviously make it unnecessarily hard, as seemingly elementary rotations will be hindered by the terrain. IMO IRS exists to compensate for downward initial stances rather than lack of floorkicks - TGM rotation doesn't really need much floorkicks, and what was needed was added in Ti. Downward stances + IRS are fun and challenging for some, while seeming an annoyance and a hindrance for others.
"The SRS floorkicks aren't optimized for 20G either, as using floorkicks to rotate a piece on a flat surface will result in the piece nudging to the right/left." it's something that takes a little getting used to. i'd say it's about the same learning curve as ars in 20g (both are pretty hard to do the right way).