+1 on sucha a great explanation from Indysteel

If you are very short, sometimes, the only bikes you fit on are the XXS bikes with the 650cc tires. Yes, the 650cc wheels are smaller, hence, likely you will be slower per pedal spin. However, if the small bike fits better than a bigger bike with 700cc, then you made the right bike decision.

As for the crankset, the compact helps to go up the hill compared to standard cranksets. Triples are heavier, but have more gears if you ride in very hilly areas. Personally, for me, triples are slightly complicated on road bikes because, as far as I know, there are no numbers on the handlebars that let you know whether you are on the big, middle, or smallest gear (unlike my hybrid or a mountain bike).
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2012 Specialized Amira Elite, upgraded carbon handle bars, Jett saddle 143mm switched to 145mm 2012 Selle Italia Max SLR Gel Flow saddle

2011 Specialized Ariel Sport,suspension post,Serfas Rx Women's Microfiber saddle