Strahinja,
don't get me wrong, Full Frame is the way to go mid-term to long-term, but there are more things to consider than image quality.
I once moved from a 1000D to a 550D (great camera even today) and then subsequently purchased 5D Classic and 5D2.
In 2014, I sold all my Full Frame gear. Why?
I'm 40+ now and find it increasingly cumbersome to carry a heavy camera bag to scenic locations. Druid Arch and Angel Arch (Canyonlands The Needles) come to mind.
Unless Canon were to bring a SL1 sized FF camera, I'm done with FF. Yes, Full Frame can give You an edge in landscape photography, way better signal-to-noise ratio in every singe picture element, better high-ISO, better bokeh (with fast, expensive glass). But is it worth to break your back for it?
If You're a Pro, You have no choice but to go FF. Personally, I have found that with careful metering and technique, I can achieve great results out of today's APS cameras, and Lightroom is a great help to get the most out of the tiny pixels.
Don't start FF with an old 28-135 zoom lens. You have to always consider the very best glass You can afford in the first place, maybe a 24-105L or 24-70L2, later on a 16-35L-IS and a 70-200+L. It's an increasingly expensive hobby, and always has been.
One photog said to me, he went Full Frame after his hobby started to pay out. He makes enough money out of wedding p. and soccer-moms-p. to justify a slowly growing high-end collection of Canon's finest.
Lucky him.


