Oh absolutely. Put up a raw uncompressed image and I can tell the difference between full frame and APS frame DSLR, and I can tell you if you were shooting with cheap glass or expensive glass.
Since the point and shoot you mentioned shoots in jpg only (unless ELPHS have really changed) then, I could spot the difference on any monitor at any resolution in the blink of any eye. Jpgs stick out like a sore thumb after you’ve worked with uncompressed images for even a small amount of time.
Now in fairness, I will say that if you’re viewing your pictures on a cheap 20” Twisted Nematic monitor (Which is probably 90% of monitors sold) I couldn’t tell the difference between the two SLRS, but I could spot the jpg.
Not with the Canon Hacker's Development Kit (CHDK).
It has the same processor Canon DSLRs, and with CHDK you can do the same things the more expensive DSLRs can do.
That was my point.