With the compact, it is typically 34/30-1 = 13% harder on the low end (you lose about a full gear for climbing) and 1-50/53 = 6% slower on the top end for the same rear cassette. There is little difference in ease of shifting between double and triple for comparable quality components. With the compact double there will be more instances of "double shifting" (shifting front and rear at the same time ot maintain cadence) but this is no big deal.

IRD makes after-market 10-spd cassettes with bigger ranges than the standard Shimano or Campy ones: For example 11/24 or 12/30. They don't shift quite as smoothly as the OEM's but are okay. They typically also require a mtb rear derailleur.