#DIV/0 and #VALUE - do error messages slow down your spreadsheet?

I don't recall seeing any performance penalties due to errors like this.

I put together a quick test:
1) Make a lookup table -- since linear lookups are good and slow calculations that potentially make good test functions for this.
1a) Fill column A with =ROW() to get a column of numbers
1b) Fill column B with =RANDBETWEEN(0,10). Copy and paste as values so they don't change.
2) Run some lookups that will sometimes result in errors and see if computation time is effected.
2a) One formula =VLOOKUP(RANDBETWEEN(1,1e6),$A:$B,2,FALSE)/VLOOKUP(RANDBETWEEN(1,1e6),$A:$B,2,FALSE). Make enough copies so that you can measure calculation time (My machine is slow, but 40 copies took about 7 seconds).
2b) Two formula. Wrap 2a in IFERROR() =IFERROR(VLOOKUP(RANDBETWEEN(1,1e6),$A:$B,2,FALSE)/VLOOKUP(RANDBETWEEN(1,1e6),$A:$B,2,FALSE),-1). Again, took about 7 seconds.
3) Repeatedly press F9 to measure computation time.

In my test, I could not see a difference in computation time, though there were several #Div0 among the results. My guess is that the use of IFERROR() is not about faster computation times.