I picked up an Ultegra 12/30 cassette for my Mount Ventoux climb in July. I have it on my Cervelo R5 with a SRAM Red long cage rear der and a 50/34 crankset on the front. I have the cassette on the bike and it is a nice climbing cassette. My power seems better when I hit the steeper switchback in the lower gear because my legs do not load up as much. There is one awkward step in the middle of the cassette where the cadence always seems too high or too low.

I would opt for the compact double and 12/30 cassette but there is nothing wrong with a triple if it is available, the width "Q" factor is okay and it works with the frame.

SaiKaiTai, have you climbed Old La Honda yet? That is a great test hill for gearing combinations.