Good news, I ended up having time to do it tonight!
THE MYSTERY HAS BEEN SOLVED......
Let me start off by saying that this was really simple to do, and I really encourage you guys to do it yourselves too. Here's the steps:
Using Google Earth, I located a point as close to 652' away from each building. Then, once I found that point, I viewed the view from that point on Google Maps. Next, I took a ruler, and measured in centimeters the height of the building in that view. (Measurement will vary from mine depending on the resolution of your monitor).
** At 652' away, the 622' point of the roof on Tower of the Americas was not visible, but it doesn't really matter because ToA wasn't in question anyway.
Here are the results from a distance of 652', give or take a foot:
Weston Centre---> 4.6 cm
Grand Hyatt San Antonio---> 4.4 cm
Marriott Rivercenter---> 4.3 cm (Pyramids) / 4.1 cm (Roof) / 4.6 cm (Spires)
Tower Life---> 4.2 cm (Base of Antenna) / 3.9 cm (Top of Roof)
Bank of America Plaza---> 4.0 cm
As we suspected, the mechanical penthouse is higher than the pyramids.
Now, time for some math. We can now figure out the heights and compare them to the heights on Emporis. We will base it off of the Weston Centre using a proportion: 4.6 = 444. To find the height of one of the others, take its height in centimeters and multiply it by 444. Then, divide by 4.6.
Results:
Weston Centre---> 444'
Grand Hyatt San Antonio---> 424.7'....Emporis: 424'....
Marriott Rivercenter---> 415' (Pyramids) / 395.7' (Roof) / 444' (Spires)....Emporis: 441' / 546'....
Tower Life---> 405.4' (Base of Antenna) / 376.4' (Top of Roof)....Emporis: 404'....
Bank of America Plaza---> 386.1'....Emporis: 387'....
SO, Grand Hyatt is 9' taller than the pyramids on the Marriott. The Weston Centre is the same height as the spires on the Marriott; they're tied. I like the Weston Centre more myself, so I'm going to claim the Weston as the tallest. When viewing Tower Life, my eye is drawn to the top of the roof and not the base of the antenna. So, for me visually, the skyline now goes as this:
1. Tower of the Americas - 622'
2. Weston Centre - 444'
3. Grand Hyatt San Antonio - 424'
4. Marriott Rivercenter - 415'
5. Bank of America Plaza - 387'
6. Tower Life - 376'
Kevin, you may now change Emporis to accurately reflect the Marriott