90-95% of us don't have a front crash bar anymore. That front strut tower brace did wonders for me.
Yes, removing the front crash beam in order to fit a big FMIC certainly reduces front'end chassis stiffness.
Without a crash beam, the only thing tieing the front of the car together is the radiator support which is quite flimsy in comparison.
So I'm sure in that case, a sold FSTB helps and is slightly better for handling than no crash beam at all although a crash would still be worse.
Nevertheless. removal of the crash beam can increase the amount of damage that occurs when a front end collision occurs, even a small ones.
As a matter of fact, my car hit a deer in 2004 shortly after I installed an ED FMIC which Hector had given me a good price on.
The repair bill was over $6k because a new radiator support added significantly to the bill.
Luckily, the repair shop was mum about it with the insurance adjuster but as soon as I got the car home, I put the crash beam back in.
And gave the ED FMIC to my friend Jeff Lepper when he later installed my Stage 3 turbo kit for me.
I noticed right away that the car handled better in the twisties with the crash beam reinstalled.
But as mentioned, I didn't notice much difference with the removal of the FSTB.