A viewer commented on the vast difference in speed between the TI36X Pro and the CASIO fx991EX it's something I am very aware of, but not something that is much of a factor in terms of the way I typically use the calculator.

I thought he made a good point and that I would make a short video showing just how different the speed is between a variety of calculators when estimating a definite integral.

LEADERBOARD:
[Some other info collected from comments and my own experimentation since the video was made]
Free42 (HP42 sim on smartphone) nearly instantaneous (1E09 precision)
Free42 (HP42 sim on smartphone) 0.5 s (1E30 precision)
CASIO fxCG50 less than 0.5 s
TINspire CX CAS less than 1 s
CASIO fx9860GII less than 1 s
CASIO CLASSPAD CP400 1.5 s
CASIO fx991EX CLASSWIZ 3 s
TI30X Pro MathPrint 3 s
HP 15C Collector's Edition 4.5 s (FIX 9 precision)
CASIO fx5800P 4.1 s
CASIO fx991CW 5.2 s
TI 36X PRO 8 s
TI Voyage 200 9 s
TI86 12 s
CASIO fx991ES PLUS 2nd edition 13.6 s
TI 68 16 s
Citizen SRP 350 18 s
Casio fx115MS 25 s
SHARP ELW516X 29 s
HP 42S 49 s (comparable to FIX 9 precision)
HP 15C approx 60 s (for 3 decimal precision)
HP 15C 8+ minutes (for FIX 9 precision)