I would. Raced IM France a few years ago and I have good w/kg. I still appreciated that 30T cog because I could very easily spin over anything without any significant lactic buildup and I stayed nice and fresh for the run.

I 2nd this. I managed Mt. Mitchell on 11-28, but if I was a tri-person I'd have hated that run afterwards if there was one.

Especially if you don't train for low rpm climbing.

What are the chainrings on your crank?

Hardly any difference between those two....

How steep? What is your prefered cadence on a climb? W/kg you expect to average?

As already stated, 28 to 30 is insufficient difference so don't waste your money. Put at least a 32 on there if you want lower gears for mountains.

This is a good one to look at, a 36/28 will climb better than a 39/28 or 39/30 while a 50/11 might cost you a touch of downhill top speed vs a 53/11 you can still be doing close to 50mph with a 90 cadence. Can also beat the larger jumps at the low end of the range going with an 11-30 or 11-32.