Minutes of Fall 2014 USA Rules Committee meeting posted on SSA website

Exactly, when a finish line is used in conjunction with a steering point
it is a much safer option than a finish cylinder. The steering point
should be the same for all classes, or at least in the same area so that
all traffic is coming to the airport from the same direction and gives
the pilot the option of doing a flying or rolling finish...

Cheers
Luke Szczepaniak

The line vs. cylinder is not about geometry, it's about altitude. If you're all coming in the same direction at low altitude over houses and quarries, that doesn't help all that much.

A finish line -- which really means a low minimum finish altitude -- is a maneuver requiring delicate management of energy and last-minute landout options. 500 extra feet makes a world of difference in a last 5 mile landout.

Interesting observation at Hobbs last year, that none of the "new" (startng nationals since 2000 -- sadly not many) pilots had ever flown a line. Regionals don't use them, so there is precious little opportunity to practice this special skill. Which we promptly had to use. One famous pilot landing on a city street about 5 miles out.

Hank, oh hank, why did you have to stir this up?

John Cochrane.