Holley...theres a reason we took the "thermo-bogs" off and threw them in the trash and replaced them with Holley's back in the day.Holleys are wayyyyy easier to tune and we would rather be out driving our cars then playing with a "plastic" crab..
Off course there is....everyone brought into the hype.
The big problem "Back in the day" was overheating the phenolic resin of the TQ carb. While the Holley is easier to tune than a TQ for sure, once the TQ is properly tuned in, you'll never touch it again unlike the Holley.
Mileage wise, your worried about nothing. A properly tuned carb no matter the make or size will do well.
Your TQ is a smog era carb. Not the best idea for a performance mided engine. Go back to the TQ link above and click around. David has a TQ for you and he's is excellent with them.