Is the 600D (T3i) good enough in 2020?

DJSanjay wrote:

I can get a decent example from ebay in used but good condition, but is the image quality going to be disappointing? I'm concerned because the sensor might be "too old". I also read somewhere that the autofocus system in newer cameras is better but just how bad is it in the 600D?

Thank you.

Since you asked this question, I can infer that you are new to photography. And if that's correct, then don't worry about sensor quality. All DSLR's produce amazing image quality, speaking of which get those old cameras for the purpose of learning, not for long term investment. If video is not important, get the 50D instead, much better than 600D in terms of flexibility and usability (you can add video via Magic lantern hack, but that's another battle). if you go for the 50D, get the SD->CF adapter.

My first DSLR is 600D and I love it. But I outgrew it early because I need fps, tracking accuracy and AF consistency, because of which I got a used 50D and later a used 7D. 
The problem with autofocus is also true to some extend, when with my 600D, I got the 50mm f1.8 II and 85mm f1.8. Wide open, there is an inconsistency in nailing AF and after getting Sigma 17-50 f2.8, the front focus issue is becoming a real problem, which are corrected later in 50D and 7D with AF Microadjust feature which the 600D doesn't have.

Because those camera do not have the modern DPAF, the live view AF is almost non-useable in real work.

Now for walk-around, I use the SL3 (250D) which have a higher resolution OVF AF module because of which the AF accuracy, precision and lowlight sensitivity is far greater than all the old cameras, except in tracking.