Canon t5 to SL2?

All I can say is I went from the super high specced D5300 sensor and AF (for the time) and the sensor still is class leading or close to it and it's from 2014 - to the 2013 18MP SL1 with it's supposedly poor DR and AA filter etc....

OOC JPEGS much better, AWB MUCH better, RAW files much better and less work.... Just as much clarity and sharpness etc with similar lenses and Canon Colours to me are like Fuji's - real nice - Nikon is always too cool for me and needs working in post... Always clips too much with the highlights....

Spec sheets tell 5% of the story is what I learned...

Nikon APS-C Cameras usually always have higher specs than Canon ones and DXO ratings etc, but what I see when I load my SD card from my SL1 does not lie...

TLDR = You'll be just fine but do not expect much difference bar a half stop better low light.

My d5300 at 3200 is like my SL1 at 6400 basically and I'd imagine t5 would be compared to a SL2 also.

18mp vs 24mp is nada. Print a tiny bit larger at 300ppi....

Don't expect much IQ difference essentially

Though the SL2 should operate / shoot faster (continuous FPS), have a better buffer and write speeds etc due to newer processor. And Live view I believe is better due to dual pixel AF

But as for IQ - outside of low light you'll likely notice not much difference.  I've shot with 6d, 5d II, Nikon D5300, Fuji X-100 T and SL1 - most shots you would not be able to tell. except for if you want bokeh or supreme low light clean high ISO

One photographer I follow used an Fuji 16MP XT-1 and now an XT-2. Photos look the same. Likewise my D5300 24mp photos and SL1 photos look the same (but I prefer the SL1 files.)

Peace.