i've owned different 'stiches for about 10 years now. started with a size 38, i'm up to a 46. damn things keep shrinking on me. ( : i haven't noticed too much of a difference between them. i certainly wouldn't buy the two-piece for the option of removing the jacket during pit stops, as it's not very easy to reattach if you're already wearing the pants. whether i've owned a one- or two-piece, i've usually worn a duty belt around my waist (sans gear, heh heh). at stops, i just unzip the jacket, and let it flop over. if you do get a 'stich, heed this advice: GET THE OPTIONAL HIP PADS. as good a company aerostich is, it appalls me that they don't include the hip pads as standard. if you have a get off, there's a real good chance you're gonna land on that nice bony hip bone. GET THE HIP PADS. ( :
the advantage i see to the two-piece 'stich (don't know about olympia options) is you can add the zip-in ellipse between the jacket and pants to accommodate a forward lean and/or give a little more room to the shoulder/crotch area.
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i forgot to add, if you're the type that is tempted to not wear the protective pants because it's just a quick ride and it's too hot, get the one-piece. don't have that temptation to seperate the gear.
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shameless spam content: i'll likely be selling two, possibly three stiches i own right now---a blue/gray 46S one-piece made in '00 (i'll have to check); a black 48S two-piece made in '03 (20th anniversary); and possibly a 44S hi-viz one-piece made in 2003 (20th anniversary). keep an eye out in the for sale section in a few weeks.
hth,
dean
cincinnati