Recently I bought the Canon 6D with a Sigma 35mm f1.4 "A" lens to use with it (no kit for me).
Until then I had used digital cameras that were limited in the ISO's available (ISO 400 or under), glacially slow AF, questionable framing (DP2 Merrill). As a result I had adopted a shooting style that is best described as "cross-your-fingers-and-maybe-you'll-get-lucky". If I missed a shot opportunity I'd think "No worry. Another moment will come along pretty soon." As a result, choosing a winning shot was incredibly easy. Because the cameras were SO bad if I got anything right I considered it a sign from the digital God.
But with the 6D that's all changed. I now have a camera that can can produce clean shots in color at ISO's as high as ISO 6400 (and BW at even higher ISOs) and focus faster than I can say "Uh..". So instead of having one (or possibly two) well-exposed, well-framed shots from an outing that might be worthy of a gallery exhibition I have 20 or more that I have to choose from. All fantastic catches, all perfectly focused and framed. The 'miss' factor has dropped exponentially. "@#$!!!", life was SO much easier with cameras with limited capabilities.
I'm sorry I ever got this thing!