First things first. For arguments sake, I'm calling the ring of seats the "gondola" and the mechanism that picks up the gondola the "catch car."
The gondola at one time did indeed spin twice on the way to the top. At one time I knew why they switched it from two to one and the reasoning escapes me but I can tell you this much, it has nothing to do with capacity. The gondola spinning is powered by either one or two (exactly how many eludes me) motors which are attached to inflated rubber tires on the "legs" of catch car as well as four unpowered nylon wheels underneath the gondola. My educated guess as to why the gondola does not currently rotate probably has to do with one of the motors failing.
The reasoning for the change in speed up the tower from slow to fast has everything to do with less wear and tear on the 4 cables attached to the gondola and not so much the motors. It took them a few seasons to actually get to the speed it ascends now. It used to ascend the tower at a much faster speed but they had to keep slowing it down due to the wear and tear on the cables.
The ride is slowed down via the white fins on the tower that slide thru the magnets that are attached to the gondola. It comes to a complete stop via four landing buffers which I believe are hydraulically powered. When the ride is ascending the tower, these are the buffers that are sticking up. So there is no actual brake that brings the gondola to a stop. For what it's worth, there are four other cells that stay lowered the whole time, these are in fact the cells which weigh the gondola. If the load is too heavy, the operators must remove a few guests to get the weight within tolerance.
The actual style of seat belts has changed thru the years. The ones that are on now have not changed in length since the day they were added and they have been on for quite awhile now. Seat belts were added for the 2000 season. I do not know exactly why they were added but my educated guess it has something to do with PGA incident in the summer of 99 which closed ours for the remainder of the season. Fun fact: most of the black seats that are on today are from the Volcano coaster at Kings Dominion.
Speaking of Kings Dominion, the gondola on the Drop Zone at Kings Dominion is far much lighter then the one KI has (lighter frame, no motors to spin the gondola, ETC) which is why theirs can ascend the tower at a much faster speed; less wear and tear on the cables. So the idea that KD's does not rotate due to KD wanting increased capacity is wrong.
The bottom line here is Drop Zone/Tower requires alot of maintenance and where alot of maintenance is involved, there's usually alot of money involved and we all know the all mighty dollar will trump any kind of operational concern. Hope this helps!
Nick: Read your statement wrong. My bad.