Deal with the new 105 a lot at work, took one of our demo bikes out the other week and have to say it is nice but not as nice as Sram. Sram has a far more positive feel when selecting a gear and as mentioned it is lighter than Shimano's 105, it depends on what bike you will be using it on and budget. Shimano is cheaper, it is also far more readily available. You can walk into most respectable bike shops and pick up a replacement part, Sram would probably have to be ordered as most Sram stuff on stock tends to be their MTB kit. The double tap is great, means no flappy brake lever! Go test ride some bikes with the new 105 and Rival 22, see which you prefer.